Geological Survey Professional Paper 58 The Guadalupian Fauna

THE GUADALUPIAN FAUNA.
By GEORGE H. GIRTY.

The first descriptions of the Guadalupian fauna were published nearly fifty years ago. This early account of Shumard's was meager enough, but gave promise of a facies interesting and novel among the known Carboniferous faunas of North America. The following pages add largely to our knowledge of Guadalupian life, and I believe more than make good any promise contained in the previous account. Nevertheless, even the collections of the Guadalupian fauna here described fail to do justice to its richness and diversity, and the present report is completed with the hope of returning to the subject after another visit to the Guadalupe Mountains.

Although a description of this range and the adjacent region can be found elsewhere, a repetition of the more important facts will conduce to a better understanding of the geologic relations of the fauna described herein and will serve to illustrate the references to localities and horizons necessarily involved in the paleontologic discussion.

The Guadalupe Mountains are situated chiefly in southeastern New Mexico, but extend across the border for a short distance into the trans-Pecos region of Texas. Save only for this southern extreme both their geology and their topography are practically unknown, and it should be understood that anything hereafter said of them relates only to that portion.

These mountains form a north-south range of considerable height, which rises abruptly from an arid and treeless plain, stretching westward to more mountainous elevations, the Cornudas Mountains and the Sierra Tinaja Pinta. This plain is locally known as Crow Flats and forms a part of the Salt Basin (Pl. I). It is now used as cattle ranges, water being raised by windmills. The only permanent surface water consists of salt lakes—broad, shallow pools incrusted with saline deposits, which in the early days were extensively sought for domestic use. This water is of course unfit for consumption, but cattle seem as a rule not to mind the less highly impregnated waters brought up by the pumps. These vary considerably in the amount and character of their saline contents, but even the best is unsatisfactory for human use.

PLATE I. MAP OF SALT BASIN AND PARTS OF THE BOUNDING RANGES (click on image for a PDF version)

On the east side, from the foot of the mountains the land slopes gradually eastward and merges with the plains of Texas. There are springs of sweet water and perennial streams on this side of the range, such streams being in this region, as a rule, associated only with the highest mountains. Usually the canyons and sandy channels serve merely to carry off the occasional torrential rains, and this is the case for the most part even with the perennial streams, which almost immediately on striking into the plain are drunk up by the soil. Beyond their debouchure from the mountains their course is merely a dry sandy channel. There are, however, flowing streams east of the Guadalupes, one such being Delaware River. In seasons of rain this watercourse is formed by the confluence of numerous small tributaries—some leading back into the mountains—which pour their sudden waters through channels usually dry; but the source of the perennial stream seems to be a very definite point situated some distance east of the Guadalupes and generally referred to as the "headwaters of the Delaware." This expression would naturally be taken to have a more general significance, but Shumard uses it, I believe, in this local sense, and as it is often difficult to fix references to local geography it seems desirable to make the present record of the fact. At this point, which is also known as Huhling's ranch, three springs, one of them strongly charged with sulphur, break out close together in the bed of the Delaware, which below this point is a permanent watercourse.

The Guadalupe Mountains are formed by uplifted strata, consisting of a thick limestone series above and a thick sandstone series below. The abrupt termination of the limestone in an almost sheer precipice of practically its entire thickness not far south of the New Mexico border marks the termination of the formation and of the Guadalupe Mountains proper. The sandstone, however, continues southward, forming a westward-facing escarpment, which with the adjacent foothills and outliers is known as the Delaware Mountains.

The southern branch of the old Santa Fe trail passed up Delaware River and close around the base of Guadalupe Point, as the abrupt, precipitous termination of the range is commonly designated. The ruined walls of a blockhouse situated near the mouth of Pine Spring Canyon bear witness to the days when a stage route passed this way. Now, however, the trail has been long unused, and heavy washouts have rendered it in places impassable, so that a traveler approaching from the west would be compelled to make a considerable detour to the south if, as in our own case, he was necessarily hampered by wagons. After again coming nearly abreast of Guadalupe Point the road passes up Guadalupe Canyon (Pl. II), which penetrates the mountains in a direction nearly north and south and contains toward its head a little spring called Guadalupe Spring. Before reaching the spring, however, the trail turns to the east and, rising to the level of the plateau by a short though steep ascent, extends northward past the ruined caravansary which stands at the mouth of Pine Spring Canyon. This canyon is situated almost on the flank of El Capitan, the spur which bounds it on the south forming the most satisfactory if not the only avenue of ascent to that peak. Near this spring was the site once, probably in the old staging days, of an encampment of regulars, evidences of whose occupancy are not rare—a brass button or an empty cartridge being the least frequently found. Nearly every adjacent peak is surmounted by a cairn, probably raised by their hands, while on an eminence near by, from which a sweeping view can be had across the eastward plain, a number of small tumuli, containing, it is said, only ashes, appear to mark the stands of outposts or sentries. A hint of the occasion for the presence of troops at this point is furnished by a stone erected beside the road in Guadalupe Canyon, which bears a date somewhere in the early sixties, I believe, and above two crossed arrows an inscription commemorating the death of a Mexican guide at the hands of Indians.

PLATE II. GUADALUPE POINT, EAST SIDE, VIEW NORTH UP GUADALUPE CANYON. The massive crag exposes 1,200 feet of the Capitan formation; the softer beds below are the Delaware Mountain formation. (From a photograph by R. T. Hill.)

The party to which I belonged camped at Pine Spring, and during the eleven days of our stay were made the different trips that furnished the collections on which the present report is principally based. The other collections from the Guadalupe Mountains included in this report are comparatively unimportant, but, on the other hand, I am entirely indebted to my colleagues for valuable collections from other areas.

In view of the highly fossiliferous character of some of the strata, our collections, though considerable, are less extensive than would be expected if the fruits of eleven days' work in some other fields were used as a standard. Owing to the height and steepness of the mountains themselves and the broken character of the country at their base, it is in many places no easy matter to reach points comparatively near by, and it will probably be necessary for those who purpose to visit the Guadalupe Mountains with the intention of collecting fossils to calculate on expending more than the usual time and labor.

The lowest beds in the Guadalupe section are limestones, very black in color and formed in rather thin and even beds. These are exposed in some dry canyons south of Guadalupe Point to a thickness of perhaps 200 feet, the base not being seen. These limestones are succeeded by a heavy series of variable beds, chiefly of sandstone. There are also strata of calcareous sandstone, of dark shale, and of dark- and light-colored limestone. The conditions of deposition appear to have been fluctuating, not only vertically but laterally, prominent beds of sandstone seen in cliff sections dying out and appearing with rather remarkable abruptness. Including the black limestone, this portion of the section was found by Richardson to attain a thickness of about 2,225 feet, and he gave it the name Delaware Mountain formation. A bed of dark limestone above the sandstones and below the white limestone deserves especial mention because of references in the literature to it and because of the distinctive fauna which it contains. The succeeding formation, called by Richardson the Capitan limestone, consists of massive limestone measuring about 1,800 feet in thickness. The color of these beds is in general white, but they are in places tinged with red and yellow. Much of the rock is a pure limestone, but at least one considerable stratum is dolomitic, having the structure of pisolite; and other beds, especially. in the lower part, have a sandy texture, which may be due to the same cause.

The Guadalupe Mountains are a structural range with a precipitous western escarpment which has been ascribed to faulting, but which at its southern extremity, as Richardson has shown, can be explained as an unsymmetrical broken fold. At all events, in the main range the beds dip to the east at a rather high angle, their abrupt termination on the west forming the mountain's side in that direction. It must not be thought, however, that the Guadalupe Mountains are, like the Delawares, really a plateau with a gradual descent toward the Pecos from a level near the top of the Capitan limestone. On the contrary, the eastern slopes are difficult and rugged. Erosion in this direction has cut away the Capitan and part of the Delaware Mountain formation, and the present surface of the plateau at Guadalupe Pass is formed, locally at least, by a bed of limestone, such as has already been mentioned, occurring about two-thirds of the way up in the Delaware Mountain formation.

In its eastern spread the Capitan limestone has been limited by erosion, and probably owing to the same cause its southern extension abruptly terminates in a bare and lofty crag. Mounted as it is upon the entire thickness of the Delaware Mountain formation, this bold headland has an appearance singularly monumental. It is known pretty generally as Guadalupe Point or Guadalupe Peak. Although the most imposing, this is not the highest point of the range, for just beyond it to the north rises another which overlooks it. This peak has been called El Capitan, and I have, when called on to refer to it, retained this name, which is further perpetuated in the Capitan limestone (Pls. II, III).

PLATE III. A (top), GUADALUPE POINT FROM A GREATER DISTANCE AND MORE DIRECTLY FROM THE SOUTH. The Delaware Mountain formation is well shown underlying the massive Capitan limestone. (From a photograp by G. B. Richardson.) B (bottom), GUADALUPE MOUNTAINS FROM THE WEST. In the foreground are the salt deposits of the Salt Basin, from which rises the bold profile of the range. At the right is the precipitou front of the Guadalupe Point, and back of it the loftier summit of El Capitan. (From a photograph by G. B. Richardson.)

Owing to the conditions of structure and erosion above described, the general level on the west side of the fold and fault, where the streams show several hundred feet of the basal black limestone, is lower than on the east, where erosion has cut down only part way through the overlying sandstones. While the Capitan limestone terminates precipitously at Guadalupe Point, these sandstones continue in a long southward extension, their westward-facing escarpment being known as the Delaware Mountains, from which circumstance they have received the name of the Delaware Mountain formation. West of the Delawares and some distance south of Guadalupe Point rise the Diablo Mountains, formed by an elevated block of the Hueco formation, to which reference will be made later.

The first accounts of the geology and paleontology of the Guadalupe Mountains were published by the two Shumards in 1859 and 1860.a As geologist of the expedition under Captain Pope, dispatched to discover artesian waters in the arid lands of the Southwest, George G. Shumard obtained some collections of fossils from the south end of the Guadalupes, which were subsequently described by his brother. Shumard does not give a clear account of the structure of the Guadalupe Mountains, but his section is as follows: b

Section of Guadalupe Mountains (Shumard).

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aTrans. St. Louis Acad. Sci., vol. 1, 1856-1860, pp. 273-297, 387-403.
b Idem, p. 280.

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The sequence of the formations in this region is obvious and in the more recent accounts remains practically as described by Shumard, although more accurate measurements have since been made, the upper limestone and the sandstone proving to be even thicker than indicated by him, while no subsequent observer has reported so much of the basal black limestone. Fossils were obtained from the three upper members of Shumard's section, those from the two limestones being later described by B. F. Shumard and proving to have each a rather distinct facies. The two formations were distinguished in the paleontologic account as the "dark limestone" (bed 2) and the "white limestone" (bed 1). Apparently the "white limestone," the "dark limestone," and the sandstone were regarded by Shumard as belonging in the Permian.

For many years after Pope's expedition this immediate region does not figure in geologic literature, although one of the main routes of travel, the Santa Fe trail, passed around Guadalupe Point.

The next observer on record is R. S. Tarr, who in 1892 published a paper in which he describes the geology of the southern part of the Guadalupes.a This author gives the following section as measured at the point of the mountains (Guadalupe Point): b

Section at Guadalupe Point (Tarr).

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aBull Geol. Survey Texas No. 3, 1892, pp. 9-39.
bIdem, p. 29.

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A detailed section partly through the white limestone at McKitterick Canyon is also given by Tarr. He clearly states the monoclinal structure of the range and describes its precipitous western scarp as probably due to faulting. His tentative conclusions regarding the correlation of the Guadalupian section with that of central Texas is supported by too little and opposed by too much evidence to warrant adoption. He found that there was nothing in the Guadalupian section to correspond lithologically with the Permian ("Red Beds") of Texas, and concluded that the Guadalupian section lay below the Permian and was probably of the age of the "Upper Coal Measures" of Texas and the Mississippi Valley. In view of the completely different fauna of the Guadalupian, this question must still be regarded as unsettled.

Some time later R. T. Hill visited this region, but he has not yet published an account of his observations. The year following (1901) B. F. Hill and I made a trip as nearly as possible over Shumard's old route, but from the west eastward, and therefore in an opposite direction. The present work is a final report of that trip, being an amplification of the short paper which I wrote at that time on the geology and paleontology of the Guadalupes.c Meanwhile G. B. Richardson has made a general reconnaissance of the Guadalupe Mountains and adjacent regions, and to his accounta the reader should refer for more authoritative information regarding points here only lightly touched.

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cAm. Jour. Sci., 4th ser., vol. 14, 1902, pp. 363-368.
aBull. Univ. Texas Min. Survey No. 9, November, 1904, 119 pp., 11 pls.

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In my brochure of 1902 the thickness of the upper limestone, including Shumard's "dark limestone," was given at 1,700 to 1,800 feet, that of the underlying sandstone as 2,000 to 2,500 feet, and that of the basal black limestone as 500 feet exposed. The chief point made was in relation to the faunas, which were shown to be very different from anything known elsewhere in America. On this account "Guadalupian" was introduced as a regional term, provisionally to include the entire rock series exposed near Guadalupe Point, but more specifically centering about the upper portion, the white and the dark limestones. Note was also made of the resemblance of the Guadalupian fauna to certain faunas of Asia and Europe.

Although Richardson made only a reconnaissance, his report on the region under consideration is the most accurate and complete which we yet have, for the formations were described and mapped over an extensive area. The highest member of the series he named the Capitan limestone and the underlying beds the Delaware Mountain formation. The latter name includes both Shumard's "dark limestone," the great sandstone series, and the basal black limestone. Richardson states that in view of the small extent of the black limestone in the area mapped (it is exposed only in the immediate vicinity of Guadalupe Point), it was thought best for the time being to regard it as a member of the Delaware Mountain formation rather than as a distinct formation. The fauna of this bed, however, at present appears to have a rather distinctive facies and is kept separate in this report. With somewhat less reason the upper limestone of the Delaware Mountain formation (Shumard's "dark limestone") has been distinguished from the main body of the formation, which in the vicinity of Guadalupe Point consists chiefly of sandstone. The fauna of this upper limestone appears to have a rather well-marked facies, while lithologically in this immediate region the limestone is distinguishable both from the sandstone below and from the Capitan limestone above. Furthermore, for the purpose of correlating my horizons with Shumard's, it is desirable to recognize this zone; and it is as yet a little uncertain whether the fauna is more closely related to that of the Capitan or that of the Delaware Mountain sandstone. Accordingly, in the Guadalupian section I distinguish the basal black limestone, the Delaware Mountain formation, the "dark limestone," and the Capitan limestone, all but the last being comprised in the original Delaware Mountain formation. The basal black limestone, however, is not known to occur elsewhere than in the vicinity of Guadalupe Point, while in the southern Delawares the "dark limestone" can not be recognized as a separate member. In this connection I may recall that Richardson's observations indicate that, whereas in the vicinity of Guadalupe Point the sandstones greatly predominate in the Delaware Mountain formation, these rocks become largely replaced by gray limestones to the south.

In point of thickness Richardson found that only 200 feet of the basal black limestone are exposed. At its greatest exposure the Delaware Mountain formation ranged to about 2,300 feet, but its base was there concealed by the Salt Basin deposits. At Guadalupe Point he measured 2,025 feet exclusive of the basal black limestone. The Capitan limestone he gives at 1,700± feet at the scarp of Guadalupe Point; our own measurement was 1,800 feet to the top of the still higher peak, El Capitan (Pl. III).

As to structure, Richardson's conclusions seem to be that the uplift was a fold in the southern part of the field visited by him, passing into a fault in the northern part, the zone of transition apparently occurring in the vicinity of Guadalupe Point.

Since the scheme of mapping employed by the Survey demands that the Guadalupian series be called categorically either "Permian" or "Pennsylvanian," it seemed best to refer it to the Permian, because of the very different and at the same time younger facies of the faunas, even that of the basal black limestone, as compared with the Pennsylvanian of the Mississippi Valley region, and because the underlying Hueco formation has a fauna more nearly comparable to that of the Russian Gschelstufe, which underlies the Russian Artinsk and Permian.

Neither Richardson nor any other observer has determined what immediately precedes or immediately follows the Guadalupian series, and this remains one of the important problems awaiting investigation in this region. It is true, Tarr says that above the massive limestone is another series of limestones and sandstones which are found only on the highest points in Texas, but which farther to the north, in New Mexico, are well developed and form the bulk of the mountains. He made no section of these beds, but states that they can not be less than 1,000 feet in thickness,a and again: "The total section exposed in the Guadalupes, approximately stated, can not be less than 4,000 feet, including the New Mexico series, which exist above the white limestone."a I do not know what rocks are intended by this indefinite statement. The Capitan limestone is not known in Texas, so far as I am aware, save in the Guadalupe Mountains and the foothills adjacent, where no overlying series is exposed. It must of necessity extend northward into New Mexico, unless faulted out, but all our faunas from New Mexico, so far as I have examined them, show an altogether different facies, one more suggestive of the beds which there is every reason to believe really lie below the Guadalupian.

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aBull. Geol. Survey Texas No. 3, 1892, p. 31.

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The formation underlying the Guadalupian is the Hueco. The typical exposures of this formation are in the Hueco Mountains and the higher beds are uplifted to the east in the Cornudas Mountains and the Sierra Tinaja Pinta. Still farther east the Hueco beds are concealed by the Salt Basin deposits, and in the Guadalupe Mountains we have an altogether different series, even the basal member of the Guadalupian having a fauna widely different from that in any zone of the Hueconian. The structure in the vicinity of the Guadalupe Mountains, the stratigraphic relations of the Hueco beds with underlying formations, and the biological character and relations of the Guadalupian fauna all point to the position of the Guadalupian series as overlying the Hueco formation. By how large an interval the highest known exposures of the Hueco are separated from the lowest known exposures of the Guadalupian can not be told, but at present it is not supposed to be great.

We owe our first account of the Guadalupian fauna to B. F. Shumard, one or two of the bryozoan forms having, however, been turned over for description to Prout.

The following table shows the species cited by Shumard and the names under which they appear in the present report:

Fossils from Guadalupe Mountains described by B. F. Shumard.

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aTrans. Acad. Sci. St. Louis, vol. 1, 1859, p. 387.

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Shumard recognized 54 species among the fossils collected at that time, 26 of which were described as new. As based on recent collections made in the Guadalupe Mountains and adjacent regions the Guadalupian fauna now known contains 326 forms, and the resources of the fauna at present appear to be almost inexhaustible. Collections which did justice to its richness and importance would greatly enhance the number distinguished in this report. The 326 forms at present constituting the Guadalupian fauna belong to the different zoological groups in the following quotas.

Zoological groups represented in the Guadalupian fauna.

As shown by this list the Guadalupian fauna manifests an unusually symmetrical development, for while it is true that the brachiopods predominate, the other groups also are represented in a proportion which is seldom equaled. It is also an extremely rich fauna, for it should be borne in mind that our collections are not exceedingly extensive. In few other regions would an equal amount of material have furnished so great a variety of species, a fact due in part no doubt to the unusual thickness of the Guadalupian section.

The Guadalupian species are mostly small as compared with those of other regions and with the average in the groups to which they belong. An exception, striking because of its isolation and degree, is found in Fusulina elongata, one of the most abundant and characteristic Guadalupian species and probably the largest Fusulina that science has yet brought to notice. Aside from this, the Foraminifera are rather poorly represented in comparison with some late Paleozoic faunas, though they are probably less completely studied than any of the other groups.

The sponges, if certain peculiar forms be allowed to remain under that designation, are, on the other hand, unusually abundant and varied, developing some novel and characteristic types of structure.

Coelenterates are more rare, small, and poorly differentiated. The absence of forms like Lonsdaleia, Michelinia, and the stromatoporoids, such as are found in some of the Asiatic faunas, is worthy of note, as is also the presence of Cladopora, which is a rather characteristic fossil of some of the lower beds. On the whole, however, the coelenterate fauna is rather meager and colorless.

Echinoderms are rare, the most noticeable being a new genus of cystidians. The presence of crinoid stems, however, shows that the true crinoids, such as occur in some of the related faunas, are present, though none of the heads have been found.

Except for one or two types the Bryozoa are rather scanty, and contain little that is striking or highly novel. The series of forms which I have assembled under Domopora is so important an exception to this statement, however, as almost to contradict it. These forms, which find their closest allies apparently in the Mesozoic, rather than in the Paleozoic, occur nowhere, so far as I have been able to discover, except in the trans-Pecos region. They form one of the most abundant and one of the most characteristic features of the Guadalupian bryozoan fauna. Acanthocladia guadalupensis is equally abundant but less peculiar.

Among the Brachiopoda, which demand a somewhat more detailed consideration than the other groups, the strophomenoids show an unusual generic differentiation, in which the presence of the rare genus Geyerella and of several species of Streptorhynchus is noteworthy. Orthotetes guadalupensis, a characteristic species of the Capitan, is likewise a unique type. The presence of Richthofenia and Leptodus also forms a novel and important feature of the Guadalupian fauna.

The Productidae, while fairly numerous, are not so highly differentiated as in many other faunas. We note the comparative absence of large species of the semireticulatus group, and the entire absence of the fimbriati, a group which includes such common forms as Productus punctatus, P. humboldti, or our own P. nebraskensis. No forms related to P. horridus of the European Permian have been brought to light, while the Marginifera group also appears to be wanting. There are a few singular types, such as P. limbatus, P. pileolus, etc., while the development in the "dark limestone" of a group of small, strongly arched shells with deep sinus, of the general type of P. semireticulatus, though with more or less faint ribs and wrinkles, may be mentioned; but as a rule the Chonetes and Producti do not stand out in strong relief. Aulosteges, however, is rather remarkably differentiated, though I have not found it in any abundance.

The Orthis group is rarely encountered. No other type is yet known than Enteletes, and with one exception the species all belong to the ventrisinuate group.

The dorsisinuati, which develop such peculiar species in the faunas of India and the Carnic Alps, are represented by only one imperfect specimen. In the upper beds of the Guadalupian (Capitan formation) this group appears to be absent.

Compared with some faunas the Pentameridae are poorly represented. To some extent this is true of the Rhynchonellidae also, since they present less variety, both in species and genera, than, for example, the Salt Range faunas. In the group of Pugnax bisulcata, however, the Guadalupian possesses a feature which is both characteristic and abundant. The absence of Uncinulus, Terebratuloidea, Rhynchopora, etc., may here be noted.

The Terebratulidae are highly differentiated and present at least one new generic type.

The Spiriferidae are represented by a number of genera, but show less variety in their specific representation. In the genus Spirifer especially we miss group after group which is found in faunas more or less related, the representation being restricted practically to Spirifer mexicanus and its allies. The Spiriferinas, on the contrary, show a high differentiation. Many of the species belong to the group of S. billingsi, which is rather characteristic of the Guadalupian. S. welleri is also a marked species.

The Athyridae and the Retziidae call for little comment. Like Ambocoelia, Composita is rather an American genus, though not exclusively so, and it is also rather abundant in the Guadalupian fauna, where it is represented by a novel and interesting type. The absence of Cleiothyridina is perhaps deserving of mention.

The remaining groups may be passed over with less comment, for while not meanly developed they show few peculiarities of note. Among the pelecypods a unique Guadalupian type is the group of species referred to the genus Camptonectes, which seems to have an analogue nowhere else in the Carboniferous, so far as I have discovered. The remainder of the Guadalupian pelecypods, while new in their specific characters, are more like the generality of Carboniferous faunas. The Pterias seem to be unusually differentiated, and we notice the absence or rarity of certain types common in many other Carboniferous faunas, such as the large Myalinas, the Edmondias, and the genus Pseudomonotis. Shumard, it is true, cites Monotis speluncaria in this fauna, but it is uncertain what form he actually had in hand, and in this, as in other instances, my comparisons are made exclusively with the collections which I have been able to study.

The gasteropods show few points of note. The development of the Pleurotomarias is perhaps a little extraordinary, as is the slight representation of the Bellerophons, which include, however, what is probably a representative of the Indian genus Warthia.

The Cephalopoda are evidently of the late Paleozoic type, but show less differentiation than might have been expected. Indications are not lacking, however, that at favored localities, which I was personally not fortunate enough to discover, the group is very plentiful, and that subsequent collections will show the Guadalupian Cephalopoda to have been highly differentiated.

The Crustacea are, with the exception of the trilobites, poorly represented. Decapods, which Gemmellaro found in some abundance in his Sicilian faunas, are unknown, and Ostracoda, which are apparently rather common in the Permian of Europe, are rare. The trilobites, not the least interesting section of this group, are however, fairly abundant, and show a construction which apparently is typical of a new genus.

The highest horizon at which Guadalupian fossils were obtained is the top of El Capitan, which by our barometric measurements is 1,800 feet above the base of the Capitan limestone. Here, from the summit and just below, I collected the following species (station 2905):

This fauna, it will be observed, consists almost exclusively of Protozoa and sponges. A considerable thickness of white limestone carrying the large Fusulina elongata so thickly packed and so uniformly laid down in one direction as almost to appear as if arranged by hand, is an interesting feature of this locality. At what appears to be the same point Richardson obtained the following (station 2966):

This fauna is more varied than that which I obtained, and has, consequently, more of the typical Capitan facies, but my own efforts at collecting were limited by stress of time to picking up a few specimens on the way down.

By far the best point which we found for collecting in the Capitan formation was halfway up Capitan Peak (station 2926), midway in the formation which bears its name. Here the fauna is extensive and varied, as shown by the following list of species collected by B. F. Hill and myself:

Anthracosycon ficus var. capitanense.
Virgula neptunia.
Virgula rigida.
Virgula rigida var. constricta.
Pseudovirgula tenuis.
Guadalupia zitteliana.
Guadalupia zitteliana var.
Guadalupia cylindrica.
Guadalupia cylindrica var. concreta.
Guadalupia favosa.
Cystothalamia? sp.
Steinmannia americana.
Sollasia? sp.
Lindstroemia permiana.
Campophyllum texanum?
Domopora? terminalis.
Fistulipora grandis var. guadalupensis.
Leioclema shumardi?
Fenestella capitanensis.
Acanthocladia guadalupensis.
Acanthocladia sp.
Goniocladia americana.
Crania sp.
Streptorhynchus gregarium.
Derbya sp. a.
Orthotetes guadalupensis.
Orthotetes declivis.
Orthotetes distortus.
Orthotetes distortus var. campanulatus.
Geyerella americana.
Orthothetina sp.
Chonetes hillanus.
Productus waagenianus.
Productus semireticulatus var. capitanensis.
Productus occidentalis.
Productus latidorsatus.
Productus? pileolus.
Productus pinniformis.
Aulosteges medlicottianus var. americanus.
Richthofenia permiana.
Spirifer mexicanus.
Spirifer mexicanus var. compactus.
Martinia rhomboidalis.
Martinia shumardiana.
Squamularia guadalupensis.
Squamularia guadalupensis var. subquadrata.
Squamularia guadalupensis var. ovalis.
Ambocoelia planiconvexa var. guadalupensis.
Spiriferina billingsi.
Spiriferina billingsi var. retusa.
Spiriferina evax.
Spiriferina sulcata.
Spiriferina pyramidalis.
Spiriferina welleri.
Composita emarginata.
Composita emarginata var. affinis.
Hustedia meekana.
Hustedia meekana var. trigonalis.
Pugnax? bisulcata var. seminuloides.
Pugnax swallowiana.
Pugnax elegans.
Pugnax shumardiana.
Rhynchonella indentata.
Rhynchonella longaeva.
Camarophoria venusta.
Dielasma spatulatum.
Dielasma cordatum.
Dielasma sulcatum.
Dielasma? scutulatum.
Dielasmina guadalupensis.
Notothyris schuchertensis.
Notothyris schuchertensis var. ovata.
Heterelasma shumardianum.
Heterelasma venustulum.
Leptodus guadalupensis.
Oldhamina? sp.
Edmondia? bellula.
Parallelodon multistriatus?
Parallelodon politus.
Pteria guadalupensis.
Myalina squamosa?
Schizodus securus?
Camptonectes? papillatus.
Camptonectes? sculptilis.
Camptonectes? asperatus.
Aviculipecten infelix.
Aviculipecten laqueatus.
Aviculipecten sublaqueatus?
Euchondria? sp.
Pernipecten obliquus.
Plagiostoma deltoideum.
Limatulina striaticostata.
Myoconcha costulata.
Cypricardinia? contracta.
Pleurotomaria mica.
Pleurotomaria putilla.
Pleurotomaria discoidea.
Pleurotomaria neglecta.
Euconispira obsoleta.
Trochus? sp.
Zygopleura swallowiana.
Foordoceras shumardianum.
Anisopyge perannulata.

This may be regarded as the typical Capitan fauna, and the fact that in so short a time and in relatively so small an amount of material we were able to obtain over a hundred species attests the richness and variety of life during the Capitan epoch.

About the same horizon, or one a little higher, was visited on the peak above Pine Spring, on the north side of Pine Spring Canyon, but this locality (station 2902) did not prove fruitful. I obtained only the following species:

The facies of this fauna recalls that obtained at the top of El Capitan (station 2905).

The lower beds of the Capitan furnished fossils from two widely separated stations. One of these is the hill southwest of Guadalupe Point (station 2906), where a detached block of the Capitan limestone is faulted to a much lower level than that on the crest of the range. At this locality fossils are plentiful, but their preservation is poor, as the rock appears to be more or less altered and many of the specimens are crushed or distorted. The fauna obtained here, which comes from immediately above the "dark limestone," has almost identically the facies of the middle portion. In the brief time at my disposal I obtained the species named below:

Amplexus sp. ?
Cladopora spinulata.
Domopora terminalis.
Domopora ocellata.
Leioclema shumardi.
Acanthocladia guadalupensis.
Derbya sp.a.
Orthotetes guadalupensis.
Orthotetes declivis.
Chonetes subliratus.
Productus semireticulatus var. capitanensis.
Strophalosia cornelliana.
Spirifer mexicanus.
Martinia rhomboidalis.
Martinia shumardiana?
Squamularia guadalupensis.
Squamularia guadalupensis var. ovalis.
Spiriferina evax.
Spiriferina welleri.
Composita emarginata.
Hustedia meekana.
Hustedia meekana var. trigonalis.
Hustedia papillata?
Pugnax elegans.
Rhynchonella longaeva?
Leptodus americanus.
Aviculipecten sublaqueatus.
Pleurotomaria? sp. C.
Anisopyge perannulata.

The other point at which fossils were obtained from the lower Capitan was in McKitterick Canyon (station 2932). The rock, a dense white limestone, lies conveniently at stream level, and the horizon appears to be in the lower part of the formation. Fossils proved scarce, and almost no time could be given to the search for them, so that I obtained only two species—Spiriferina sulcata? and Dielasma prolongatum.

The character and status of Shumard's "dark limestone" are somewhat uncertain to me. The cliff at Guadalupe Point contains at its base an undetermined thicknessa of dark limestone, which was presumably the bed referred to by him, but the precipice was too abrupt to scale and no fossils were obtained. Again, on the hill southwest of Guadalupe Point, beneath a whitish limestone (station 2906) having the lithology of the Capitan and a fauna closely related to that collected from the middle of the formation (station 2926) occurs a not very thick series of dark limestones (station 2924), which are also supposed to represent the "dark limestone" of Shumard. I obtained here the following forms:

Fusulina elongata.
Cladopora spinulata.
Domopora? terminalis.
Fistulipora grandis var. guadalupensis.
Fenestella sp. c. var.
Acanthocladia guadalupensis.
Productus popei?
Spirifer mexicanus var.
Hustedia meekana.

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aFifty feet, according to Richardson.

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On both occasions when we ascended Capitan Peak, as nearly as possible the same route being selected, the contact between the Capitan and Delaware Mountain formations was concealed by talus. My notes contain no reference to the rocks of this horizon in the vicinity of Pine Spring, but from loose blocks on the north side of the canyon (station 2930) I collected a considerable amount of material which probably belongs to the "dark limestone." The following list represents the fauna obtained from this source:

Fusulina elongata.
Endothyra sp. a.
Endothyra sp. b.
Spirillina aff. S. plana.
Polysiphon mirabilis.
Steinmannia americana.
Lindstroemia permiana.
Lindstroemia permiana var.
Lindstroemia cylindrica.
Lindstroemia sp.
Cladopora spinulata.
Archaeocidaris sp. c.
Archaeocidaris sp. d.
Domopora? terminalis.
Domopora ? ocellata.
Domopora? constricta.
Domopora? vittata.
Fistulipora grandis var. guadalupensis.
Stenopora granulosa.
Stenopora sp.
Leioclema shumardi.
Fenestella guadalupensis.
Fenestella guadalupensis var.
Fenestella spinulosa?
Polypora mexicana?
Polypora sp. C?
Acanthocladia guadalupensis.
Acanthocladia sp.
Crania sp.
Derbya sp. a.
Chonetes permianus.
Chonetes hillanus.
Chonetes subliratus.
Productus semireticulatus var. capitanensis.
Productus popei.
Productus popei var. opimus.
Productus indentatus.
Productus occidentalis.
Productus? pileolus?
Productus limbatus.
Productus sp. d.
Aulosteges guadalupensis.
Richthofenia permiana.
Spirifer mexicanus.
Spirifer mexicanus var.
Spirifer sp. a.
Spiriferina billingsi.
Spiriferina laxa.
Spiriferina hilli var. polypleurus.
Spiriferina welleri?
Composita emarginata?
Hustedia meekana.
Hustedia meekana var. trigonalis.
Hustedia papillata.
Hustedia bipartita?
Pugnax bisulcata.
Pugnax bisulcata var. seminuloides.
Pugnax bisulcata var. gratiosa.
Pugnax swallowiana?
Pugnax osagensis?
Pugnax bidentata.
Pugnax pinguis.
Pugnax sp. a.
Rhynchonella? indentata.
Dielasma spatulatum.
Dielasmina guadalupensis.
Notothyris schuchertensis var. ovata?
Myalina squamosa?
Aviculipecten guadalupensis.
Aviculipecten sp. a.
Euomphalus sulcifer.
Euomphalus sulcifer var. angulatus.
Anisopyge perannulata.
Cythere? sp.

The position of this loose material was such that little if any could have come from high in the Capitan, and little if any from below the top of the Delaware Mountain formation. The rock is a limestone partly dark colored and partly a light brown. The fauna shows rather marked differences from that obtained midway in the Capitan formation, species occurring in one which are not found in the other, or being abundant in one and rare in the other. On the other hand, there is a considerable community of forms. Some of the more distinguishing characteristics of this "dark limestone" fauna are the abundance of Fusulina elongata, which, though occurring in the greatest profusion at the top of the Capitan (station 2905), seemed to be absent from the point where our typical Capitan fauna was obtained (station 2926), the greater abundance of cup corals, the presence of Cladopora spinulata, the greater abundance of the Domoporas and other Bryozoa, the presence of Chonetes permianus and C. subliratus, the abundance of small Producti of the semireticulatus group, such as P. popei, P. indentatus, etc., the presence of Aulosteges guadalupensis and Spiriferina laxa, the abundance of the group of Pugnax bisulcata,a the presence of Aviculipecten guadalupensis, and of Euomphalus sulcifer and its variety angulatus, and the abundance of Anisopyge perannulata. An equal number of distinctive forms might be named on the part of the Capitan fauna. The faunas of stations 2926 and 2930 are marked by about the same differences which originally distinguished Shumard's "dark limestone" from his "white limestone," but our more extensive collections show more differences than his rather meager ones. I believe, therefore, that our collection 2930 is Shumard's "dark limestone" fauna, and that it is represented stratigraphically by a not very thick series of dark-colored limestones occurring at the junction of the Delaware Mountain formation with the Capitan. The Capitan fauna, as exemplified by the collections obtained in its middle portion at station 2926, and the fauna of the "dark limestone" show well-marked differences, and suggest the question whether the latter should be grouped as a lower division of the Capitan, as a distinct member, or as a portion of the Delaware Mountain formation.

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aOnly a single specimen of this species is contained in our collection from station 2926, and the lithology suggests that it may really have come from the "dark limestone."

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For purposes of stratigraphy it would perhaps be more convenient to divide the two series in the vicinity of Guadalupe Point at the top of the sandstones, but lithologically the "dark limestone" shows greater resemblance to the dark-colored calcareous members of the Delaware Mountain formation in which Richardson has included it, than to the white limestone of the typical Capitan.

Faunally, if we consider only the collections made in the sandstones of the Delaware Mountain, the "dark limestone" is quite different from that division and would probably have to be regarded as a distinct series, or, better, as a subdivision of the Capitan. Evidence will appear in its turn, however, which indicates that the "dark limestone" is really a part of the Delaware Mountain formation.

Before turning to the discussion of the typical Delaware Mountain fauna it will be desirable to comment on some collections from the upper series made by R. T. Hill. They were obtained at the south end of the Guadalupe Mountains, at a horizon described merely as the "upper limestone." They may, consequently, have come from either the "dark limestone" or the Capitan. The species identified are as follows:

Station 3762.

Productus semireticulatus var. capitanensis.
Fusulina elongata.
Endothyra sp. a.

Station 3762a.

Fusulina elongata.
Fistulipora grandis var. guadalupensis.
Acanthocladia guadalupensis.
Spiriferina welleri var. a.
Hustedia meekana.

Station 3762b.

Lindstroemia permiana?
Lindstroemia sp.
Zaphrentis? sp.
Amplexus sp.
Cladopora spinulata.
Archaeocidaris cratis?
Domopora? terminalis.
Domopora? ocellata.
Fistulipora grandis var. guadalupensis.
Acanthocladia guadalupensis.
Chonetes permianus.
Richthofenia permiana.
Hustedia meekana.

Station 3762c.

Archaeocidaris sp. a.
Acanthocladia guadalupensis.

Station 3762d.

Lindstroemia permiana var.
Domopora? terminalis.
Domopora? ocellata?
Fistulipora grandis var. guadalupensis.
Leioclema shumardi ?
Acanthocladia guadalupensis.
Hustedia meekana.
Dielasma spatulatum?

Station 3762e.

Lindstroemia permiana var.?
Cladopora spinulata.
Domopora? terminalis.
Domopora? ocellata.
Fistulipora grandis var. guadalupensis.
Leioclema shumardi.
Fenestella hilli.
Polypora mexicana?
Acanthocladia guadalupensis.
Acanthocladia sp.
Richthofenia permiana.
Spiriferina laxa?
Hustedia bipartita?

In no instance do these lists indicate the fauna obtained from the middle portion of the Capitan limestone, and several appear to present the fauna of the "dark limestone." Lots 3762b, 3762d, and 3762e are the most clearly indicative of the "dark limestone" and 3762 and 3762c the most ambiguous. From the manner in which the Fusulinas are preserved in lot 3762, I am disposed to believe that it came from the highest beds of the Capitan. It has been provisionally assigned to this horizon in the records published here, and the other collections have been placed in the "dark limestone."

From the sandstones of the Delaware Mountain formation I obtained material at only three points, and since fossils are not so abundant or so well preserved in these sandstones as at other horizons my collections are a little meager. From about 250 feet above the base of the formation (station 2919) the following forms have been identified:

Fusulina elongata.
Fistulipora grandis var. guadalupensis.
Enteletes sp. d.
Chonetes subliratus.
Productus waagenianus var.
Productus texanus?
Productus sp. a.
Productus guadalupensis.
Spirifer sp. b.
Martinia rhomboidalis.
Squamularia guadalupensis.
Composita emarginata?
Hustedia papillata.

The two other collections were obtained at about the same level, approximately 700 feet up in the formation. One of these (station 2903) furnished the following species:

Fusulina elongata.
Fusulinella sp. a.
Chonetes sp.
Productus waagenianus var.
Productus texanus.
Productus sp. a.
Productus latidorsatus.
Productus walcottianus.

At the other (station 2931) I obtained the forms named in the following list:

To these may be added a collection made by Mr. Elder from one of the limestone members in the Delaware Mountain formation not far above the last two. Here (station 2963) he obtained five species, as follows:

Fusulina elongata.
Stromatidium typicale?
Cladopora spinulata.
Fistulipora grandis var. guadalupensis.
Stenopora polyspinosa var. richardsoni?

In the same region, but from a somewhat higher horizon (station 2968), Mr. Richardson collected the following species:

Lindstroemia permiana var.
Paraceltites elegans.
Gastrioceras sp.

As disclosed by these collections, the fauna of the Delaware Mountain formation presents many differences from either that of the "dark limestone" or that of the Capitan formation. The chief positive difference consists in the development of a relatively extensive suite of Pelecypoda and Gasteropoda, in the main very unlike those which succeeded them. Negatively, the Brachiopoda are less abundant and well differentiated. Consequently many of the forms characteristic of the series next above are wanting. The brachiopods which are present are in part the same, but the Productus fauna of this division seems to be distinct from that of either the "dark limestone" or the Capitan.

The black limestone at the base of the Guadalupe section is not as a rule highly fossiliferous, but would surely furnish an interesting and extensive series of forms if carefully collected. I had time to essay the black limestone at only one point. It was not found to be fossiliferous there except near the top (station 2920), where I obtained the following species:

Anthracosycon ficus.
Anthracosycon ? sp.
Enteletes sp. C.
Orthotetes? sp. a.
Chonetes sp.
Productus latidorsatus var.
Richthofenia permiana.
Composita mexicana var. guadalupensis.
Hustedia meekana.
Pugnax nitida.
Pugnax osagensis.
Pugnax bidentata.
Rhynchonella longaeva?
Leda sp.
Plagiostoma deltoideum?
Pleurotomaria strigillata.
Pleurotomaria arenaria var. monilifera.
Euomphalus sulcifer.
Foordoceras shumardianum var. praecursor.
Peritrochia erebus.
Bairdia aff. B. plebeia.

A collection from about the same locality and horizon (station 2967) brought in by Mr. Elder presents to a considerable extent a different facies, as follows:

Stenopora granulosa?
Enteletes sp. c.
Meekella attenuata.
Meekella multilirata.
Aulosteges sp. a.
Aulosteges sp. b.
Richthofenia permiana.
Spirifer sp. b.
Composita mexicana var. guadalupensis.
Hustedia meekana.
Hustedia papillata?
Pugnax? pusilla.
Solenomya? sp.
Clinopistha? cf. C. radiata var. laevis.
Nucula sp. a.
Nucula sp. b?
Yoldia sp.
Aviculipecten sp. a?
Pleurotomaria strigillata.
Naticopsis sp.
Loxonema? inconspicuum.
Macrocheilina? modesta.
Foordoceras shumardianum var. praecursor.
Agathoceras texanum.
Paraceltites elegans.
Anisopyge perannulata.
Anisopyge? antiqua.

This fauna is unusually well balanced, containing Brachiopoda, Pelecypoda, Gasteropoda, and Cephalopoda in nearly equal proportions, besides a corresponding share of other groups. At this horizon, in fact, the ammonoids appear from our collections to be more abundant than at any other in the typical Guadalupian section. It is interesting to note that they have a Permian aspect, an indication which is corroborated by the presence of Richthofenia and Aulosteges. While unmistakably related to the overlying faunas, that of the basal black limestone has an individual facies. It is widely different from any of the known faunas of the Hueco formation, and without doubt is to be regarded as a member of the Guadalupian series. It may be remarked that neither as a lithologic nor as a faunal unit is this limestone known to occur except in the immediate region of Guadalupe Point.

In the section exposed at the south end of the Guadalupe Mountains there are, according to our collections, four rather well-marked faunas, which occur in the basal black limestone, the Delaware Mountain formation, the "dark limestone," and the Capitan formation.

As already remarked, in the Delaware Mountain formation, which even in the vicinity of Guadalupe Peak is more or less interspersed with dark limestone, the calcareous component appears to become more and more important as the strata are followed southward into the southern Delawares, where almost the whole of the section is composed of limestone beds. This area was not visited by me, but collections were made by Mr. Richardson and Mr. Elder from a number of different localities and horizons. From a point 7 miles north of Marley's ranch (station 2935) Mr. Richardson obtained the following collection:

From the low hills west of Marley's (station 2936) the two following species were collected: Chonetes permianus and Ambocoelia planiconvexa var. guadalupensis. A collection made 1-1/2 miles east of Marley's ranch (station 3501) contains four forms, as follows:

Enteletes sp. d.
Derbya sp. a.
Meekella skenoides.
Spirifer sp. b.

At another point, about 15 miles north of Marley's (station 3500), the following species were collected:

At about the same locality as the foregoing was obtained the largest of all the faunas collected in the southern Delawares (station 2969). The following species have been identified:

At station 2957, which is situated 45 miles south of El Capitan, the following species were collected:

About 20 miles north of the railroad station called Plateau (station 2962) Mr. Elliott collected the following:

In a collection made 10 miles northwest of Kent (station 2964) the following species were identified:

Finally, a small collection made 35 miles northeast of Van Horn (station 2965) furnished Pugnax? bisulcata var. seminuloides and Waagenoceras cumminsi var. guadalupense.

These collections from the limestones of the southern Delawares have a fauna which is somewhat ambiguous. In the main it seems to be that of the "dark limestone" of the Guadalupe Mountains. This is suggested by the Bryozoa and corals and by the abundance of Pugnax bisulcata var. seminuloides, Chonetes permianus, etc. In no instance is there a recurrence of the characteristic fauna found near the middle of the Capitan formation, yet in a good many of these collections Capitan species have been identified which in the Guadalupe section have not been found in the "dark limestone." I refer to Goniocladia americana, Productus? pileolus, Heterelasma shumardianum, H. venustulum, and a few others. The sandstones of Guadalupe section have to a considerable extent different species. Nevertheless, in view of the facts that we still know the Guadalupian faunas very incompletely, that lithologically these limestones of the southern Delawares resemble those of the typical Delaware Mountain sections, that from observations in the field they appear to replace and represent the sandstones of that formation, that the conditions of limestone deposition on the one hand and of sandstone deposition on the other would probably influence the character of the faunas, and that our collections from the sandstones of the Delaware Mountain were made chiefly in the lower half of the formation, while in the southern Delawares they were probably made in the upper portion—in view of these facts I am ready to believe that these southern faunas do not represent any horizon of the typical Guadalupe section above the "dark limestone." It is unfortunate that we know so little of the forms which occur in the limestones of the Delaware Mountain formation in the Guadalupe sections. I neglected them entirely, and the two collections brought in by Richardson's party are too meager to be of much service. The faunas from the southern Delawares seem to show that at least some of the Capitan species range lower than is indicated by our data from Guadalupe Point. These faunas are so closely allied to that of the "dark limestone" as to suggest that the latter belongs with them rather than with the Capitan formation. This may not mean the elimination of the "dark limestone" as a distinguishable faunal facies, for it may characterize the upper portion of the Delaware Mountain formation while the lower portion also has a facies of its own.

Although the Guadalupian series is supposed not to occur in the Diablo Mountains, this memoir involves a small suite of fossils which are reported to have come from that range. They were found among the collections of the National Museum, having been received from E. T. Dumble in 1892. On internal evidence I have divided this material into two parts. One of these appears to consist of collections made by Von Streeruwitz and mentioned in his report,a although the different lots are now intermingled so that nothing can be exactly located. This fauna is that of the Hueco formation, which Richardson found to be the dominating if not the only Carboniferous formation in the Diablo Mountains.

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aAnn. Rept. Geol. Survey Texas for 1892, 1893, p. 170.

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The remaining portion of the material differs lithologically from the other. In the main the fauna also is widely different, not only from that of the other assemblage of forms, but from anything since obtained in the Diablo Mountains, or from the Hueco fauna as a whole. It contains some striking types, such as Leptodus, which are supposed to be characteristic of the Guadalupian, and yet it is not identical with any of the known Guadalupian faunas. While of too interesting a nature to be omitted from the present report, a twofold uncertainty, therefore, surrounds this material, since a question may be raised not only as to whether it belongs to the Guadalupian fauna, but as to whether it was obtained front the Diablo Mountains. As some of the striking forms were not mentioned by Walcott, who I believe determined the fossils for Von Streeruwitz's report, it is possible to suppose that the collection was not made in the Diablo Mountains, but was sent in at the same time, possibly from the same general region, and thrown in with the Diablo forms. As to the other point, the Guadalupian fauna seems to be so extensive, and as yet so imperfectly known, that it is, theoretically at least, quite possible for local collections from a distinct area to present an individual facies and yet to belong to the same period.

The following species are present in the fauna determined in this way (station 3764), and it will be seen that the facies is considerably different from any of the faunas of the Guadalupe section or of the southern Delawares:

Lindstroemia permiana.
Cladopora tubulata.
Thamniscus digitatus.
Acanthocladia guadalupensis.
Enteletes dumblei.
Enteletes angulatus.
Enteletes sp. c.
Derbya nasuta.
Derbya? crenulata.
Meekella attenuata.
Leptodus americanus.

Two more collections are included in this report which show considerable individuality of facies and yet without much doubt belong to the Guadalupian series. They were made by R. T. Hill in the vicinity of Marathon, Tex., nearly 150 miles southeast of the Guadalupes. One of them was obtained in the Glass Mountains, 17 miles northwest of Marathon (station 3763). From this point I have identified the following species:

Fusulina elongata.
Guadalupia zitteliana.
Cystothalamia nodulifera.
Lindstroemia permiana.
Zaphrentis? sp.
Amplexus sp.
Cladopora spinulata.
Domopora? ocellata.
Domopora? hillana.
Fistulipora grandis var. guadalupensis.
Fistulipora sp.
Meekopora sp.
Acanthocladia guadalupensis.
Enteletes globulosus.
Enteletes sp. a.
Enteletes sp. b.
Enteletes sp. d?.
Streptorhynchus pygmaeum.
Streptorhynchus? sp. a.
Orthotetes guadalupensis?
Orthotetes distortus.
Orthotetes? sp. a.
Meekella skenoides.
Meekella difficilis.
Productus sp. c.
Productus guadalupensis var. comancheanus.
Productus meekanus.
Productus subhorridus var. rugatulus.
Strophalosia hystricula.
Richthofenia permiana.
Spirifer sp. b.
Squamularia guadalupensis.
Spiriferina billingsi?
Spiriferina hilli.
Composita emarginata var. affinis?
Composita mexicana.
Hustedia meekana.
Hustedia papillata.
Hustedia bipartita.
Camarophoria venusta.
Notothyris sp.
Leptodus americanus.
Parallelodon multistriatus.
Parallelodon? sp.
Pteria squamifera.
Aviculipecten sp. b.
Aviculipecten sp. b var.
Aviculipecten sp. c.
Aviculipecten sublaqueatus.
Astartella nasuta.
Pleurotomaria richardsoni?

The other locality (station 3840), which is described merely as the "mountains northwest of Marathon," has furnished the following species:

Fusilina elongata.
Platycrinus? sp.
Phyllopora ? sp.
Thamniscus sp.
Septopora aff. S. robusta.
Rhombopora aff. R. lepidodendroides.
Rhombopora? sp.
Acanthocladia guadalupensis.
Fistulipora grandis var. guadalupensis.
Meekella difficilis.
Productus subhorridus var. rugatulus.
Aulosteges magnicostatus.
Spiriferina welleri?

These two faunas are evidently related to one another and in a general way to those of the Guadalupe and Delaware mountains. Their resemblance to any of the facies manifested in those areas is far from being so close that they may be called identical, but is greater to the fauna of the Delaware Mountain sandstone than to that of the Capitan limestone, or even to that of the "dark limestone." Accordingly, I have provisionally registered these forms as from the Delaware Mountain formation.

Thus different degrees of uncertainty are involved in the faunal relation of these collections to the Guadalupe section, and in some cases in their geographic position as well, and it seems best to refer to this matter here and to omit for the most part from the account of range and distribution that follows each species the marks of query really needed to express the modified certainty with which some of the assignments are made. As a rule where an interrogation point is used it refers to the identification of the species.

In view of the different localities and different horizons represented by the subject-matter of this report the determination of the best method of arranging the illustrations of species has been a matter of some concern. Since the ultimate purpose here, as in my other work, is faunal, the use of a zoological arrangement which would obscure the original assemblages of formational or regional groups of species seemed objectionable. On the other hand, when trying to compare several species, or to consult the illustrations of only one, I have found it highly annoying to be compelled to refer to several plates. Still, the grouping to the eye of forms associated in nature seems to me too important to be lightly dispensed with, and the loss of this instructive arrangement the greater of the two evils. An attempt to ameliorate the trouble occasioned by having kindred forms distributed on several plates has been made in connection with the arrangement of the figures on the plates themselves, so that they have rather rigidly been placed in serial order. This militates against a balanced appearance of the plate, which is very agreeable; but in some works, a class of which those of Gemmellaro may be cited as instances, the illustrations are so artistically distributed that it is almost impossible to find them. After losing much time over Gemmellaro's plates and others like them, it has seemed to me that this is a matter in which utility outweighs beauty as a desideratum. Consequently the plates in this report will be found arranged according to the stratigraphic and geographic groups in which the different collections have been considered above. Although this method does not misrepresent the natural grouping, it fails to represent it completely, because I have not sought to figure the common or recurrent forms in each set of plates.

Although in one particular the present report adds considerable to the available knowledge of the Guadalupian fauna, in another its contribution is small, for geographically the fauna is restricted, so far as known, to the general region where it was first discovered. It is quite unlike the faunas of eastern North America and almost equally unlike most of those of the West which I have seen. Of the latter a very few suggest the Guadalupian in some degree, but for one reason or another, because our material is very scanty or the resemblance remote, it has seemed best to reserve these instances for future discussion. This limited distribution of the Guadalupian need not indicate an extremely local development of a fauna contemporaneous, perhaps, with others of a different facies which we already know, but it may be due to several causes—to our incomplete knowledge, especially of western faunas; to the fact that the Guadalupian beds may be represented elsewhere by strata which do not contain invertebrate fossils, such as red beds; or to the removal by erosion of a part of the Guadalupian deposits, which were formerly more extensive. Probably all three causes contribute to limiting the present knowledge of the Guadalupian territorially.

The difference manifested by the faunas of the Guadalupe Mountains from those of the rest of North America, though not necessarily, at least in fact involves a resemblance to certain Asiatic and European faunas. Rather careful comparisons have been made with these alien faunas, but although evidently related to some of them the Guadalupian seems, as indicated farther on, to maintain a highly individual facies.

Aside from the species which Shumard had described, most of the Guadalupian forms appeared to be new. So different are the Guadalupian and Pennsylvanian faunas that in most cases the species of the one have no related species in the other, but the Pennsylvanian literature has been searched with care for kindred forms, and where found the usual comparisons have been instituted. It has been found necessary, however, to import few names of Pennsylvanian species into the Guadalupian fauna. Still fewer have been introduced from foreign literature, though I have been careful to note instances where it seemed that a relationship existed. But in the latter case particularly, even when the relationship seemed rather close, the Guadalupian form has generally been given a new name, because the data were not at hand by which I could reach a conclusion as to their identity or distinction.

It is reasonably safe to depend on descriptions and figures for an identification of species where the geographic separation is not wide and where the faunal association is essentially the same, but, otherwise, characteristic specimens are necessary for a satisfactory comparison. In the present case all these conditions were conspicuously absent. The most nearly related foreign faunas were separated by a terrestrial quadrant. They prove to have in the main a very different facies, to be related in one species and different in twenty, and I was practically without foreign material with which to make comparisons when comparisons were most desirable.

It has been said not less truly than often that it is easier to combine two species that have been injudiciously discriminated than to disengage two species that have been injudiciously combined, and it is also true that loose discriminations and loose identifications lead to loose correlations. I have felt under obligation to other workers in this field to leave a species whose relationship I was unable to determine as unentangled as possible, and to establish the nomenclature on a reasonably independent and permanent basis. Consequently, in doubtful cases I have leaned consciously to the side of species making, nor would I feel deeply concerned should it prove on just evidence not now accessible to me that some of my names are synonyms.

It has been my intention to go over the literature with some thoroughness in comparing the Guadalupian with other faunas, but so wide is the field and so rich the accumulation of literature that it was evidently necessary to contract and eliminate in order ever to bring such an attempt to completion and to make the result at all commensurate with the cost in time and labor. My object being to obtain the broad and general facts as to faunal and specific relationship, it seemed safe to refer, so far as possible, to monographic works, omitting the smaller contributions of which they were the culmination, even though such omission might entail some loss in minutiae. The literature of Asia, Africa, etc., by reason of its still limited quantity was not unmanageable, and that of North America I had already pretty well in hand; but the works on European Carboniferous shells, even though my survey was restricted to the more important, were so numerous as to be impracticable for my purpose. The obvious faunal relations and the geologic position of the Guadalupian beds, however, are such that only a part of these reports were significant in this connection, and these were found to be a much more manageable quota. Even after selection of this sort the labor of comparing the Guadalupian fauna was not trivial, some of the incidental difficulties aside from those of a quantitative nature being the various languages in which these investigations were couched, with some of which I am unacquainted, and the lack of uniformity in classification and nomenclature.

In order to avoid the repeated citation of the same authorities hereafter, it has seemed best to give in brief résumé the most important works used in making comparisons of the Guadalupian fauna. Were other important works within my knowledge I would of course have had reference to them, and it is probable that some which would have furnished valuable data have been overlooked. In commencing this literary survey I may begin with the admirable work of Waagen on the fauna of the Productus limestone of the Salt Range of India,a since this fauna is geographically about as near as any which is related to the Guadalupian, and since Waagen's monograph, both in magnitude and thoroughness, is second to none with which I have had to deal. The earlier and partial accounts by Davidson, De Koninck, and others being passed over, this work is the only authority which I have employed as representing the Carboniferous fauna of the Salt Range.

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aWaagen, W., Salt Range fossils: Mem. Geol. Survey India, Pal. Indica, ser. 13, vol. 1, 1887.

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The faunas of the Himalaya are much less completely known than those of the Salt Range, and for them I have had recourse chiefly to Diener's reports, not neglecting, however, brief accounts by Davidson and Salter. The latter in 1865b issued a pamphlet in connection with Blanford, in which a limited fauna is described from Niti, in the northern part of the Himalayas. In the same work a few forms are cited from Spiti Pass, a locality which yielded Diener also some material. Davidson published in 1866 two short papers, appearing consecutively in the Quarterly Journal, one dealing with some Brachiopoda from Tibet and the other with representatives of the same group from Kashmir.c

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bSalter, J. W., and Blanford, H. F., Palæontology of Niti, in the northern Himalaya, etc., Calcutta, March, 1865.
cDavidson, T., Jour. Geol. Soc. London, vol. 22, 1866, pp. 35 et seq.

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Faunas from Kashmir sand Spiti (see above) were in 1899d made the subject of a memoir by Diener, who discussed the Spiti fauna again in 1903.e Another memoir by the same author treats of the "Permo-Carboniferous" fauna of Chitichun No. 1,e and to this fauna also he had occasion to return in 1903.f A third memoir by Diener, published in 1897, deals with the Permian fossils of the Productus shales of Kumaon and Gurhwal;g and, lastly, that put out in 1903 contains, in addition to a discussion of the Spiti and Chitichun faunas, accounts of some Permian fossils from the neighborhood of Malla Sangcha, from the Productus shales of the Lissar Valley (Johar), and from the Permian Productus shales of Byans.h The same author has given us an account of a geologic expedition in the central Himalaya,i accompanied by lists of fossils; but this work did not seem especially to concern the present investigation.

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dDiener, C., Himalayan fossils Mem. Geol. Survey India, Pal. Indica, ser. 15, vol. 1, pt. 2, 1899.
eIdem, vol. 1, pt. 5, 1903, p. 133.
fIdem, vol. 1, pt. 5, 1903, p. 3.
gIdem, vol. 1, pt. 4, 1897.
hIdem, vol. 1, pt. 5, 1903, pp. 62, 100, 114, respectively.
iDenkschr. math-naturwiss. Klasse, K. Akad. Wiss., Wien, vol. 62, reprint, 1895.

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The explorations of Kraffta and of Obrutschewb in Bokhara have furnished information of slight moment so far as the present investigation is concerned. Their reports contain lists of a few Carboniferous species in no way indicating any special relationship to the Guadalupian fauna.

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aKrafft, A. von, Denkschr. math.-naturhist. Klasse, K. Akad. Wiss., Wien, vol. 70, 1901, pp. 49 et seq.
bObrutschew, V., Materialien zur Geologie von Russland: K. min. Gesell., vol. 13, 1889, pp. 167 et seq. In Russian; no faunal lists.

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Carboniferous faunas occur also in Turkestan, but the only literature which relates to them is a report by Romanowsky published in 1880.c Romanowsky seems to have had a number of rather meager faunas, representing possibly several geologic periods. None of them shows much relationship with the Guadalupian, but I have included them pretty consistently in my comparisons.

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cRomanowsky G., Materialien zur Geologie von Turkestan, pt. 1, St. Petersburg, 1880.

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Suess and Frechd give a few rather restricted lists of Carboniferous species occurring in central Asia and Pamir, but although a few forms are figured there is little available for comparisons with the present fauna, and nothing to indicate that a comparison would prove very profitable.

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dSuess, E., and Frech, F., Denkschr. K. Akad. Wiss., Wien, vol. 61, 1894, pp. 431 et seq.

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Our knowledge of the Chinese Carboniferous is regrettably scanty. First in time and first probably in celebrity are the accounts by Kayser and Schwager in the paleontological volume of Richthofen's China.e The only Carboniferous fauna, to use the term strictly, which is here described, however, is that from Lo Ping. Fliegel somewhat revised the Lo Ping fauna in 1901,f in connection with another work, to be mentioned later. Of equal importance are the accounts by Loczy, Lörenthey, and Frech on the Carboniferous faunas collected during the journey of Count Bela Szechenyi in eastern Asia.g These faunas also are for the most part rather meager, and like that from Lo Ping the most extensive one has recently been reviewed by Fliegel.h Another expedition into eastern Asia—that made by Futterer and Holderer—appears to have obtained collections of Carboniferous material. I infer that a report on this material is in preparation, or has been completed, but I have been unable to obtain a copy of it, if it has appeared in print. The only account that has come to hand consists in a small brochure by Schellwien, entitled "The Trias, Permian, and Carboniferous in China."i It contains very little which is concerned in the present investigation. The recent Carnegie expedition into China obtained a small amount of Carboniferous material, a brief report on which is now in process of publication. These faunas, however, are so fragmentary and so unlike those of the Guadalupe Mountains that it did not seem necessary to include them in the comparisons which I have undertaken. Douville on two occasionsj has given short lists of Carboniferous fossils from China, but in neither case does the fauna appear to be closely related to that of the Guadalupe Mountains. The only other information regarding the Carboniferous faunas of China which I have come upon consists of some notes and lists by Frecha based on material collected by Richthofen but not included in Kayser's report. As the species are neither described nor figured, it did, not seem practicable to compare the Guadalupian fauna with those which they constitute. Our knowledge of the Carboniferous faunas of China as conveyed in these reports appears to be highly fragmentary and scattered, much more so than that of the Himalayan faunas, which in turn is much less complete than that of the faunas of the Salt Range.

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eKayser, E., and Schwager, C., in Richthofen, F. von, China, vol. 4, Berlin, 1883.
fFliegel, G., Palæontographica, vol. 48, 1901, p. 125.
gLoczy, L., Lörenthey, E., and Frech, F., Wissenschaftliche Ergebnisse der Reise des Grafen Béla Széchenyi in Ostasien, Wien, vol. 3, 1899.
hFliegel, G., Palæontographica, vol. 48, 1901, p. 134.
iSchellwien, E., Sonderabdruck aus den Schriften der Phys. ökon. Gesell. zu Königsberg i. Pr., 1902.
jDouvillé, H., in Jourdy, E., Bull. Soc. géol. France, 1886, p. 448; and (independently) Comptes-rendus Acad. sci., Paris, vol. 130, 1900, p. 592.
aFrech, F., Neues Jahrbuch, 1895, vol. 2, pp. 47 et seq.

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Regarding the Carboniferous faunas of the northern part of eastern Asia, the literature contains almost nothing. The only data which I have been able to discover are in a short notice by Tschernyschew b of a small collection from the vicinity of Vladivostok.

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bTschernyschew, Th., Dull. Cam. géol., St. Petersburg, vol. 7, No. 22, 1889, p. 353.

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Carboniferous rocks occur in Korea, but little is known of their faunas. Yabec has recently identified species of Fusulina, Stacheia, Bigenerina, and Lagena from the vicinity of Phyongyang. Gottsche, Credner, and Fliegel are also said to have reported the occurrence of Carboniferous fossils in this state (fide Yabe).

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cYabe, Y., Jour. Coil. Sci., Imp. Univ. Tokyo, vol. 21, art. 5, 1906, pp. 28 et seq.

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Carboniferous rocks appear to have but a limited distribution in Japan, and their faunas are largely restricted to the Foraminifera. Schwager's account of this group in Richthofen's China has already been referred to, and Yabed also has devoted especial attention to them. The other groups of fossils are not well represented in these beds and have apparently not been carefully studied. Gottsche lists a few species from Akasaki, and similar brief lists are to be found in two works by Harada.e Aside from the Foraminifera too little is known of the Japanese Carboniferous fauna to warrant a comparison with the Guadalupian. A noteworthy entry in the Japanese lists is the genus Leptodus (Lyttonia), which is a striking member of the Guadalupian as well. The Foraminifera of the two faunas, however, appear to present very different facies.

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dIdem, pp. 10 et seq., and other works in Japanese.
eHarada, T., Die japanischen Inseln, Berlin, K. jap. géol. Reichsanstalt, 1890, pp. 63 et seq.; Outlines of the geology of Japan, Imp. Geol. Survey Japan, Tokyo, 1902, pp. 34 et seq. Several works in Japanese also probably refer to the Carboniferous faunas.

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The Carboniferous is known to occur in French Indo-China, with Lonsdaleia and Schwagerina; and from Tenasserim, in Burma, Noetlingf has cited a list of eleven species combining a relationship to the Carboniferous faunas of India on the one hand and of Sumatra on the other, but none at all, or one only, showing even a remote kinship to that of the Guadalupe Mountains.

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fNoetling, F., Records Geol. Survey India, vol. 26, 1893.

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Rather more complete than anything which we have about eastern Asia is our knowledge concerning the Carboniferous of the Indian Archipelago. The earliest account was that written by Beyrich, published in 1865,g on a rather extensive suite of fossils from Timor. A few additions were made to this fauna by Martin in 1881,h and in 1892 it underwent revision by Rothpletzi from new collections, the species in many cases being redescribed and refigured. In 1880 Roemerj described a Kohlenkalk fauna from the west coast of Sumatra, which was revised by Fliegel in 1901.a In making comparisons of the Sumatran fauna, Fliegel also revised those of Lo Ping and Tengtjancsing, as mentioned above. In 1904 W. Volzb published sa rather extensive account of the geology of Sumatra, with lists of species and descriptions of a few Foraminifera and corals. Both groups present a non-Guadalupian facies.

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gBeyrich, E., Abhandl. K. Akad. Wiss. Berlin, 1864, vol. 1, 1865, pp. 61 et seq.
hMartin, K., Sammiungen Geol. Reichs-Museums in Leiden, ser. 1, vol. 1, 1881, pp. 1 et seq.
iRothpletz, A., Palæontographica, vol. 39, 1892, pp. 57 et seq.
jRoemer, F., Palæontographica, vol. 27, 1880, pp. 4 et seq.
aFliegel, G., Palæontographica, vol. 48, 1901, pp. 91 et seq.
bVolz, W., Zur Geologie von Sumatra: Geol. und pal. Abhandl. Jena, 1904, pp. 1-112.

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The Carboniferous faunas of the Australian region have been the subject of several important memoirs and a number of shorter papers. Among the latter may be mentioned a report by Etheridge, senior,c on some Queensland fossils, one by Etheridge, junior,d on some fossils from the Bowen River coal field, and one by Freche on marine Dyassic Brachiopoda. There is also of course Dana's classic account of some Carboniferous faunas from New South Wales obtained by the Wilkes exploring expedition,f but for data relating to these faunas I have relied chiefly on two summary works. One of these is De Koninck's memoir, entitled "Recherches sur les fossiles paléozoïques de la Nouvelle-Galles du Sud," conveniently translated into English and republished by the Geological Survey of New South Wales.g The other is the account of the geology and paleontology of Queensland and New Guinea by Jack and Etheridge.h Although other reports on the same faunas have appeared from the pens of Sowerby, Lonsdale, McCoy, Morris, D'Orbigny, and others, I have felt that they could justly be superseded by the two monographs mentioned, especially since the Australian faunas appear in no essential way related to those of the Guadalupe Mountains.

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cEtheridge, R., sr., Quart. Jour. Geol. Soc. London, vol. 28, 1872, pp. 317 et seq.
dEtheridge, R., jr., Proc. Royal Phys. Soc. Edinburgh 1878-80, 1880, p. 263.
eFrech, F., Zeitschr. Deutsch. geol. Gesell., vol. 50, pp. 176 et seq.
fDana, J. D. Geology: U. S. Expl. Exped. 1838-1842, under command Charles Wilkes, U. S. N., vol. 10, Philadelphia, 1849, pp. 681-730.
gDe Koninck, L. J., Mem. Geol. Survey New South Wales, Paleontology, No. 6, 1898.
hJack, R. L., and Etheridge, R., Geology and palæontology of Queensland and New Guinea, Brisbane and London, 1892.

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From Persia Mölleri cites some small suites of Carboniferous fossils; chiefly Foraminifera, with such brachiopods of Productus semireticulatus and Orthotetes crenistria. So far as one can tell from the very inadequate data, this region contains no fauna comparable to the Guadalupian. Schellwien also has published an account of some Carboniferous fossils from the Egypt-Arabian desert.j The fauna is very limited and manifests scant relationship to the Guadalupian.

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iMöller, V., Jahrb. K-k. geol. Reichsanstalt, vol. 30, 1880, p. 573.
jSchellwien, E., Zeitschr. Deutsch. geol. Gesell., vol. 46, 1894, pp. 68 et seq.

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A very interesting memoir appeared in 1878 from the pen of Abich,k consisting of a description of a late Carboniferous fauna from Djoulfa, in Armenia, which was again discussed and revised in 1900 by Arthaber and Frech.l The same year Enderle described a Carboniferous fauna from Balia Maaden, in Asia Minor.m

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kAbich, H., Geologische Forschungen in den Kaukasischen Ländner, pts. 1 and 3 (pls. 1-5), Wien, 1878. Part 3, which was not accessible to me till 1907, contains, of matter germane to this report, only the five plates without any descriptions whatever.
lArthaber G., and Frech, F., Ueber das Paläozoicum in Hocharmenien und Persien: Beiträge zur Pal. und Geol. Österreich-Ungarns, etc., Wieu und Leipzig, 1900, vol. 12, heft 3, pp. 209 et seq.
mEnderle, J., Ueber clue anthracolithische Fauna von Balia Maaden in Kleinasien: Beitäage zur Pal. und Geol. Österreich-Ungarns, etc., vol. 13, heft 2, pp. 49 et seq.

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The Carboniferous is known to occur on the island of Chios, but only a few species have been cited by Stachen and Teller.o

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nStache, G., Verhandl. K.-k. geol. Reichsanstalt, Wien, 1876, p. 371.
oTeller, F., Denkschr. math.-naturhist. Klasse K. Akad. Wiss., Wien, vol. 40, p. 344.

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The Russian section is of especial interest to the description and correlation of the Guadalupian fauna, because it contains the typical Permian. I did not, however, feel at liberty to neglect entirely the lower portion of the section, though paying especial attention to its upper members. The Productus giganteus zone, however, was regarded as being practically beyond my purview.

An extensive literature has grown up about the Russian geologic and faunal sequence, only part of which I could hope to include with profit in the comparisons undertaken here. Some papers were intentionally passed over in favor of others of a more comprehensive scope, my object, as elsewhere, being to make a general survey rather than an exhaustive one, but some works which would have served my purpose well have doubtless been unintentionally omitted. The papers which I have consulted on this subject group themselves in three categories— (1) those which describe the rocks and faunas of a single geographic or political province; (2) monographs of certain faunas or parts of faunas, and (3) monographs of certain groups of fossils. As belonging to the latter category I have used of course Möller's monograph on the Russian Foraminifera,a Stuckenberg's account of the corals and Bryozoa of the Carboniferous limestone of upper middle Russia,b Tschernyschew's memoir on the Gschelian Brachiopoda of the Urals and Timan,c Amalizky's account of the Anthracosias of the Perm-formation of Russia,d Karpinsky's monograph on the Ammonites of the Artinskstufe,e Jakowlew's account of the Cephalopoda and Gasteropoda of several upper Paleozoic terranes of Russiaf and Tzwetaev's discussions of the cephalopods of the Russian Carboniferous limestone.g

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aMöller, V., Mém. Acad. imp. sci., St. Petersburg, 7th sec., vol. 25, No. 9, 1878; vol. 27, No. 5, 1879.
bStuckenberg, A., Mém. Com. géol., St. Petersburg, vol. 5, No. 4, 1888.
cTschernyschew, Th., Mém. Com. géol., St. Petersburg, vol. 16, No. 2, 1902.
dAmalizky, W., Palæontographica, vol. 39, 1892, pp. 125 et seq.; also printed in Russian the same year.
eKarpinsky, A., Mém. Acad. imp. sci., St. Petersburg, 7th sec., vol. 37, No. 2, 1889.
fJakowiew, N., Mém. Com. géol., St. Petersburg, vol. 15, No. 3, 1899.
gTzwetaev, M., Mém. Com. géol., St. Petersburg, vol. 5, No. 3, 1888.

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In the way of monographs of certain stratigraphic zones use was made especially of Trautschold's monograph of the Moskovian,h also in the Gschelian of Tschernyschew's brachiopod monograph and in the Artinsk of Karpinsky's Ammonite monograph, reference to both of which has already been made. There is also Krotow's geologic and paleontologic monograph of the sandstone of the Artinsk,i a work chiefly in Russian, with but few of the numerous species figured, or discussed or described in German. The Permian fauna was viewed chiefly through the pages of Tschernyschew,j Netschajew,k and Golowkinsky,l including of course Amalizky's discussion of the Permian Anthracosias.

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hTrautschold, H., Die Kalkbrüche von Mjatschkowa, Moscow, 1874-1879.
iKrotow, P. I., Kazan Obshchestvo Estestvo-Ispytatelei, Trndy, vol. 13, 1885.
jTschernyschew, Th., Verhandl. Russ. k. mineral. Gesell. St. Petersburg, 2d ser., vol. 20, No. 9, 1885, p. 265.
kNetschajew, A., Kazan Obshchestvo Estestvo-Ispytatelei, Trndy, vol. 27, 1894.
lGolowkinsky, N. A., Verhandl. Russ. k. mineral. Gesell. St. Petersburg, vol. 1, 1889, p. 273.

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Amalizky has also given an account in Russian of the Permian of the Volga and Oka basins,m but the species are merely listed and the work, for my purpose, has been of little service.

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mAmalizky, W., Deposits of the Permian system in the basin of the Volga and Oka, St. Petersburg, 1887.

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The general discussions which were actually employed might have been largely increased in number without probably increasing the available data in anything like a corresponding degree. Foremost among the works used should probably be mentioned Murchison, De Verneuil, and Keyserling's account of the geology of Russia and the Ural Mountains,a which is now valuable chiefly, at least in the matter of Paleozoic paleontology, for its excellent figures. Keyserling's "Reise in das Petschora-Land"b must not be overlooked, though I recurred to it but seldom. Stuckenberg's partially illustrated account of the Gschelian and Artinskian faunas (of sheet 127 of the Russian Survey)c added valuable data to those which I was able to gather in relation to these faunas from other sources. Krotow gives a brief illustrated account of the Carboniferous faunas of the western slopes of the Urals.d Tschernyschew lists some other Carboniferous faunas and summarizes the Artinskian brachiopods in connection with his geologic report on sheet 139 (western slope of the central Urals)e The same author gives extensive lists of the Gschelian fauna in connection with his brachiopod monograph. Lists are also given by Nikitin in his paper "Artesian wells in the vicinity of Moscow,"f as well as a description of a rather small fauna of Gschelian age. Sibirzew has likewise given rather extensive lists of Moskovian, Gschelian, Artinskian, and Permian faunas,g to which I have had occasional recourse, but as a rule it has not seemed practicable to use bare faunal lists, since, aside from such question as might legitimately surround identifications without the vouching afforded by descriptions and figures, rises the task, discouraging enough for one not too familiar with the literature and synonymy of Russian species, of pursuing the identified species to their sources.

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aMurchison, R. I., De Verneuil, E., and Keyserling, A. von, Paléontologie, London and Paris, vol. 2, pt. 3, 1845.
bKeyserling, A. von, Wissenschaftliche Beobachtungen auf einer Reise in das Petschora-Land, St. Petersburg, 1846.
cStuckenberg, A., Mém. Com. géol., St. Petersburg, vol. 16, No. 1, 1898, pp. 193 et seq.
dKrotow, P. I., Mém. Com. géol., St. Petersburg, vol. 6, 1888, pp. 468 et seq.
eTschernyschew, Th., Mém. Com. géol., St. Petersburg, vol. 3, No. 2, 1886, pp. 338, et seq.
fNikitin, S., Mém. Com. géol., St. Petersburg, vol. 5, No. 5, 1890.
gSibirzew, N., Mém. Com. géol, St. Petersburg, vol. 15, No. 2, 1896, pp. 233 et seq.

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So distantly related to the Guadalupian are most of the Carboniferous faunas of continental Europe and the British Isles, and so extensive is the literature which relates to them, that I have not felt called on to convoke most of it to my comparisons. An exception has been made, for reasons previously stated, in the case of the Russian section. Faunas very important to the present investigation have been described, however, from the province of Palermo, in Sicily, from the Carnic Alps, and from the Permian of Germany and England. I have also undertaken to include in my comparisons some of the scantily known Arctic faunas.

Gemmellaro has described in parts an extensive and interesting fauna from Palermo, but the several numbers of his work are to be had with difficulty, if my experience is a criterion. Many bibliographic references to them appear to be misleading, indicating that they were private publications. Some parts may have appeared independently, but such as I have been able to obtain have been published either by the Palermo Scientific Society or the Royal Academy of Sciences of Naples. Whether he obtained and described the lower invertebrate classes I have been unable to discover; all the parts seen by me relate to the Brachiopoda, the Mollusca, and the Crustacea.

The brachiopods, so far as the volumes which I have seen are concerned, are not completely described. In 1897h he gave an account of two genera (Scacchinella and Megarhynchus) from the Fusulina limestone of Palermo, besides mentioning a number of other associated generic types. In 1899a he described a large number of species found in the Sicilian fauna, but evidently only a part of the brachiopod representation. Streptorhynchus, Derbya, Strophalosia, Aulosteges, Marginella, Richthofenia, and Lyttonia, mentioned in the preliminary notice, are omitted, and if he has elsewhere published descriptions of the species belonging to these genera I have been unable to find them. The pelecypods were described in 1897b in the same volume which contained the preliminary notice of the Brachiopoda. Part but not perhaps all of the Gasteropoda were described in 1890, the same volume containing also the description of the nautiloid division of the Cephalopoda and a considerable appendix to the Ammonoidea.c The main portion of the Ammonoidea was described in 1888.d The descriptions of the Crustacea were published in another series in 1890.e In addition to being incomplete, Gemmellaro's description of the Sicilian fauna is annoyingly faulty in another particular. Most, or probably all, of the copies lack plates referred to in the text. Several instances of this sort occur, and too frequently the citations of figures on the plates have to be corrected.

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hGemmellaro, G. G., Giorn. Soc. sci. nat. ed econ. di Palermo, vol. 21, 1897, pp. 113 et seq.
aGemmellaro, G. G., Giorn. Soc. sci. nat. ed econ. di Palermo, vol. 22, 1899, pp. 95 et seq.
bIdem, vol. 21, 1897, pp. 9 et seq.
cIdem, vol. 20, 1890, pp. 53 et seq., pp. 37 et seq., and pp. 9 et seq., respectively.
dIdem, vol. 19, 1888, pp. 1 et seq.
eGemmellaro, G. G., Reale arced. sci. fisiche e mathematiche, Napoli (reprint?), 1890.

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Somewhat similarly incomplete have been the data which I have been able to gather relating to the fauna of the Carnic Alps. The earlier Carboniferous faunas of the region are out of relation with the Guadalupian, and consequently I have neglected De Koninck's monograph on Carboniferous fossils from Bleiberg, in Carinthia.f The Brachiopoda of the younger faunas were described by Schellwien first in 1892, in a paper entitled "The fauna of the Carnic Fusulina limestone,"g and later, in 1900, in an article upon the fauna of the Trogkofelshichten.h He described the Foraminifera in 1897,i and apparently projected a discussion of the other groups, but I have been unable to find any evidence that he carried the purpose into execution. Several invertebrate faunas from the Carnic Alps not closely related to the Guadalupian have recently been described by Gortani,j and he cites other works on the same subject by himself, Angelis d'Ossat, and others. For some reason many of these citations appear to be incorrect. As an instance, for a work by himself in which Fusulina alpina var. communis is cited with synonymy, Gortani refersk to "I, Paleontogr. Italica, X, 1904." My copy of that work contains no paper by Gortani and no paper dealing with the Carboniferous of the Carnic Alps. The same is true of the volumes for the four or five years adjacent. I have, however, found a work by Angelis d'Ossat on the corals and Bryozoa of the Carnic Alps,l but the species, though described, are not figured.

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fDe Koninck, L. J., Recherches sur les animaux fossils, pt. 2, Brussels, 1873.
gSchellwien, E., Palæontographica, vol. 39, 1892, pp. 1 et seq.
hAbhandl. K.-k. geol. Reichsanstalt, vol. 16, heft 1, 1900.
iPalæontographica, vol. 44, 1897, pp. 237 et seq.
jRegny, P. Vinassa de, and Gortani, M., Fossili Carboniferi del M. Pizzul e del Piano di Lanza nelle Alpi Carniche, Rome, 1905; Rivista italiana di paleontologia, anno ix, fasc 1, 2, Bologna, 1903 (?); Atti Reale accad. Lincei, ser. 5, vol. 11, 1902, p. 316.
hFossili Carboniferi del M. Pizzul e del Piano di Lanza nelle Alpi Carniche, 1905, p. 529.
lAngelis d'Ossat, G. de, Classe sci. fisiche, mathematiche e naturali, Atti Reale accad. Lincei, Mem. ser. 5, vol. 2, 1898, pp. 242 et seq.

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I must not fail in this connection to speak of the fauna of the Bellerophon limestone. This interesting fauna from southeastern Tyrol, which has been described by Mojsissovics, Stache, and Gumbel,a shows almost no resemblance to the Guadalupian. Its facies is in fact so unusual for the Carboniferous that Gumbel held its geologic age to be lower Trias, while Stache was led to believe that it was upper Permian. The stratigraphic occurrence seems to indicate a horizon close to the top of the Paleozoic, if not even beyond the division plane which separates that terrane from the Mesozoic. Very recently Schellwien and Kossmatb have reported a fauna from the Bellerophon limestone which establishes its age as Paleozoic, and by indicating a correlation with the Salt Range Carboniferous fauna of India tends to prove that the latter is Permian throughout, instead of largely Artinskian, as claimed by Tschernyschew. In the preliminary statement of Schellwien and Kossmat only a few, the most significant types, are mentioned, such as Richthofenia aff. lawrenciana, Productus indicus, P. abichi, Marginifera ovalis, and Lonsdaleia indica, and they suggest a somewhat closer resemblance to the Guadalupian than would have been inferred from the earlier known fauna.

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aFrech states (Lethæa Geognostica, p. 551) that the nautiloids were described by Mojsissovics, the Ostracoda and Foraminifera by Gümbel, the ammonoids by Diener, and the Mollusca by Stache. I have been unable to locate the papers by Gümbel and Mojsissovics, but Stache describes the nautiloids and gasteropods in the Jahrb. K.-k. geol. Reichsanstalt, vol. 27, 1877, pp. 271-318, and the pelecypods and brachiopods in the same series, vol. 28, 1878, pp. 93-168. Diener's account of the ammonoids appears in the Sitzungsber. math.-naturhist. Classe K. Akad. Wiss., Wien, vol. 106, pt. 1, pp.61-76.
bSchellwien, E., and Kossmat, F., Zeitschr. Deutsch. geol. Gesell., vol. 57, heft 4, 1905, pp. 357-359.

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For the Permian faunas of Germany and England I have contented myself with consulting the well-known works of Geinitzc and King.d

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cGeinitz, H. B., Animalischen Ueberreste der Dyas, Leipzig, 1860.
dKing, W., Monograph of the Permian fossils of England, Palæontographical Society, 1850.

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The first account of the Carboniferous faunas of Spitzbergen appears to have been given by De Koninck in 1850,e but he had only a few species. In 1874 Toula published an account of some Carboniferous fossils from the south point of Spitzbergen,f followed in 1875 by another on some Kohlenkalk and Zechstein fossils from the Hornsund,g on the western coast of Spitzbergen, and by a description of Permo-Carboniferous fossils from the western coast of Spitzbergen (Axel Island) and the cape between the two arms of North Fjord.h More recently (1887) Lundgreni published an account of some Permian fossils from Spitzbergen, and Goesj describes a species of Fusulina from the same island. Of the Carboniferous of Nova Zembla Toula's work dealing with a Carboniferous limestone fauna from the Barents Islandsk is the only one which I have found. Anderssonl has listed some Carboniferous species from Baren Island, which is not the same as the foregoing in spite of the similarity of name and location.

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eDe Koninck, L. J., Bull. Acad. roy. sci. Belgique, vol. 16, pt. 2, 1850, p. 632.
fToula, F., Sitzungsber. math-naturwiss. Klasse, K. Akad. Wiss., Wien, vol. 68, 1874, pp. 267 et seq.
gIdem, vol. 70, pt. 1, 1875, pp. 133 et seq.
hNeues Jahrbuch, 1875, pp. 225 et seq.
iLundgren, B., Bihangtill Kongl. svensk. Vet.-Akad. Handl., vol. 13, afd. 4, No. 1, 1887, pp. 1 et seq.
jGöes, A. T. von, Oefvers. Vet. Akad., Förhandl. for 1883, No. 8, 1884, pp. 29 et seq.
kToula, F., Sitzungsber. math-naturwiss. Klasse, K. Akad. Wiss., Wien, vol. 71, pt. 1, 1875, pp. 527 et seq.
lAndersson, J. G., Bull. Geol. Inst. Upsala, vol. 4, pt. 2, No. 8, 1900, p. 243.

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Other works on Arctic faunas have been considered to some extent, as, for instance, one by Haughton,m another by Etheridge,n a third by Salter,o etc., but as a rule the known faunas are too poor and fragmentary to yield anything of interest in connection with the Guadalupian, besides being, so far as can be determined, only remotely related.

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mHaughton, S., Jour. Royal Dublin Soc., 1857, pp. 183, 239-250.
nEtheridge, R., Quart. Jour. Geol. Soc. London, vol. 34, 1878, pp. 568 et seq.
oSalter. J. W., in Belcher, E.. Last of the Arctic voyages, vol. 2, 1855, pp. 377 et seq.

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Stachea recorded several Carboniferous faunas in the West Sahara, to which, though they show no close relationship with the Guadalupian, I have assigned a place in my comparisons.

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aStache, G., Denkschr. math.-naturwiss. Klasse, K. Akad. Wiss., Wien, vol. 46, 1883, pp. 369 et seq.

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Relatively little is known of the Carboniferous of South and Central America. The earliest and perhaps on the whole the most widely known account is that by D'Orbigny,b in which he described several Carboniferous faunal occurrences, chiefly in Bolivia. Salterc a score of years later listed and partially figured a small suite of fossils from Lake Titicaca, in Bolivia, and Toulad not long there after described a small Carboniferous fauna from the vicinity of Cochabamba, in the same country. The only record of the occurrence of Carboniferous in Peru which I have come upon was made by Gabb,e and includes only four or five species. On the Brazilian Carboniferous faunasf we have primarily Derby's admirable memoirf in which, however, only the Brachiopoda are discussed. A recent publication by Katzerg gives a résumé of the Brazilian faunas as a whole. They appear to bear a remarkably close relation to those of the typical Pennsylvanian and consequently are widely different from the Guadalupian. Although there are a few types which are unknown in the Pennsylvanian, such as some of the species described by Derby, a large number appear to be the same in both faunas. Katzer's figures are in part copies from Derby, in part copies from Meek, Geinitz, and others, and in part original drawings from Brazilian specimens. Of the latter some appear to be new species, figured but not described.

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bD'Orbigny, A., Voyage dans l'Amérique méridionale, vol. 3, pt. 4, 1842.
cSalter, J. W., Quart. Jour. Geol. Soc. London, vol. 17, 1861, p. 64.
dToula, F., Sitzungsber. math.-naturwiss. Klasse, K. Akad. Wiss., Wien, vol. 59, pt. 1, 1869, pp. 433 et seq.
eGabb, W. M., Jour. Acad. Nat. Sci. Philadelphia, 2d ser., vol. 8, 1874-1881, p. 302.
fDerby, O. A., Bull. Cornell Univ., Science, vol. 1, No. 2, 1874.
gKatzer, F., Grundzüge der Geologie des unteren Amazonas Gebietes, 1903.

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Carboniferous strata occur also in Guatemala, where they were reported by Sapper.h This author lists a small number of species from each of four provinces, but the faunas appear not to be closely related to those of the Guadalupe Mountains. With this my South American citations come to a close.

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hSapper, C., Petermann's Mittheilungen, Ergänzungshefte, No. 113, 1894.

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To canvass the extensive literature dealing with the Carboniferous of North America would be impracticable at this place, nor is it called for. My comparisons, in truth, have been made less specific in the case of the North American faunas than in some others, partly because the faunas are so extensive and the literature so scattered that to do otherwise would be a serious task, partly because, being fairly familiar with the literature and the faunas, I could select what seemed most appropriate; and partly because the Guadalupian fauna differs so widely from either the Pennsylvanian or the "Permian" of the eastern section that no more than general comparisons seem to be for the most part necessary. Such comparisons as I have made, however, have been with the faunas of the Mississippi and Ohio valleys, the Appalachian region, and central Texas. The faunas of the West are for the most part so imperfectly known and correlated and so different from the Guadalupian that I have systematically left them out of consideration.

In general comparisons of the Guadalupian with the upper Carboniferous faunas of central and eastern North America I have referred back to Weller's useful bibliography.a Such additions as have been made since that work appeared do not materially alter the combined data of previous publications. In describing the Guadalupian species, however, I have intended to keep in view all the more recent literature.

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aWeller, S., Bibliographic index of North American Carboniferous invertebrates: Bull. U. S. Geol, Survey No. 153, 1898.

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The works cited in the foregoing résumé are of course only a part of those actually consulted in the course of my study of the Guadalupian fauna, but they are the ones which were used most frequently and which seemed most important to consider in connection with it.

In all these faunas there is none, I regret to say, with which the Guadalupian can really be considered closely allied. The nearest are probably those of the Salt Range and Himalaya, in India, and of the Fusulina limestone of Palermo, in Sicily; but in this judgment, in the case of the Indian faunas especially, I may have been too strongly influenced by the occurrence of those two singular brachiopod types Richthofenia and Leptodus. The fact is perhaps without especial significance, but it may be noted that the occurrences of this faunal facies, or at least the occurrences of these genera, in the three instances mentioned, occupy closely corresponding positions with regard to the earth's equator, and may indicate a zonal development in the late Carboniferous.

The resemblances shown by the Guadalupian fauna to even the most similar of those brought into comparison are sporadic and almost immediately offset by differences as great. In number and importance the differences outweigh the resemblances. My comparisons accordingly indicate that the Guadalupian has a very individual facies among known faunas, though it is probably related to several of them. Such differences would perhaps be expected from their widely separated geographic positions and doubtless from the greater freedom of migration as well as the greater susceptibility to environmental conditions possessed by some types. It is somewhat surprising, however, to find the Guadalupian fauna so completely different from anything known in the Mississippi Valley, whose geographic position is relatively so close. The differences are so great and so pervading that I shall not attempt to name them in detail, for they must be patent to the most superficial investigation. The position maintained in 1905b seems fully justified—that if the Guadalupian fauna is Permian then the Kansas "Permian" is not, for they differ too greatly for both to belong in the same epoch, or, if it should prove they were in part contemporaneous, for the same name to be applied to them. At present I believe that the Guadalupian, defined below by its oldest known fauna, is younger than the Kansas "Permian" and that it belongs to a different epoch.

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bProc. Washington Acad. Sci., vol. 22, 1906, pp. 29-25.

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Its correlation with the Russian section is, unfortunately, ambiguous. In spots it resembles the Gschelian, the Artinskian, and the Permian. As I pointed out in the paper just cited, the resemblances between the underlying Hueco formation and the Gschelian are so much more important and complete as to exclude from the probabilities a correlation of any part of the Guadalupian with any part of the Gschelian, The abundance and character of the ammonoid development in the lower and middle portions of the Guadalupian contain some suggestion of the Artinsk fauna, and the abundance and character of Streptorhynchus, Strophalosia, or Aulosteges in the middle and upper Guadalupian suggest the Permian of Russia and Germany, so that probably the best correlation is that of the Guadalupian on one hand with the Artinsk and Permian on the other; but, intrinsically, the Russian and American faunas appear to me to have but little in common.

At this point I may well mention a recent paper by Prof. Charles Schucherta dealing with the same general topics. It came into my hands after the present work had been completed and transmitted for publication, and on this account it is not perhaps receiving such ample consideration as it deserves. I have not been compelled, however, to alter my views on account of this addition to the literature, because I find them in close accord with those expressed by Schuchert, whose paper to a certain extent anticipates the enunciation of the opinions here set forth.

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aAm. Jour, Sci., 4th ser., vol. 22, 1906, pp. 29-46, 143-158.

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I would gladly evade, if I could do so, a discussion at this time of the relationship of the Guadalupian with other faunas, both at home and abroad, for such a discussion must necessarily involve the question of the so-called Permian of Kansas, and it seems to me that one can venture to express few positive opinions on this subject. The short paper published in 1905b gave my views with a freedom which I may sometime regret, and it would possibly be well to let matters rest without recurring to them here, but my studies of the past year have added a few considerations which I believe to be new, and a recent paper by Mr. Prosser,c which, among other things, comments on the aforesaid opinions, places matters in a light in which I do not wish them to remain. Mr. Prosser has the appearance of refuting the opinions and at the same time convicting me of the use of very bad reasoning or no reasoning at all. His line of argument, as I make out, is this: The Guadalupian is upper Permian; the underlying Hueco formation is equivalent to the Pennsylvanian below the Kansas "Permian" and does not include the latter; consequently my statement that "if the Capitan fauna is Permian, certainly that of Kansas is not," does not follow at all. Mr. Prosser is right. It does not follow at all. But this is Mr. Prosser's argument, not mine, and to construct it he has taken first a preliminary correlation which I made four years ago and to which I no longer adhere, then a correlation of his own which he will find it difficult to maintain, and as a conclusion half of a sentence from my recent paper which has in the context a somewhat more qualified meaning than that which is obvious in its fragmentary and isolated condition.

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bProc. Washington Acad. Sci., vol. 7, 1905, pp. 1-25.
cProsser, C. S., Notes on the Permian formations of Kansas: Am. Geologist, vol. 36, September, 1905, pp. 142 et seq.

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I used the term "upper Permian" in the title to a preliminary paper which appeared four years ago,d and to this Mr. Prosser refers in the first of his premises. Indeed, as was clearly intimated at that time, the expression "upper Permian" was used because, on the supposition that the Kansas "Permian" was properly so called, the Guadalupian fauna (chiefly characterized by station 2926, in the middle portion of the Capitan formation) is so widely different from it; because the Guadalupian is so similar in certain striking particulars to Indian faunas which competent authorities regarded as of Permian age, and because it was stratigraphically so high in the Carboniferous, situated as it is at the top of the extensive trans-Pecos section. Subsequent studies have led me to believe that it was ill advised to call the Guadalupian fauna upper Permian even in the title of a preliminary paper, and that it would be unwise at present to correlate the Guadalupian series with any definite stage of the Russian section. The qualification of my earlier inference was rather clearly indicated in my 1905 paper,a where I called attention to a resemblance between the Guadalupian fauna and that of the Fusulina limestone of Sicily, which Tschernyschew correlates with the Artinsk. The Artinsk, I need hardly recall, underlies the typical Russian Permian and is by some Russian authors included under the same designation, but by others is distinguished under a separate name as Permo-Carboniferous. In the same connection, regarding the Guadalupian I said: "Several circumstances leave me still of the opinion that this bed may be Permian." It seems to me that to anyone reading the paragraph in which these passages occur it must be apparent that I no longer hold to the assignment of the Guadalupian to the upper Permian. I would infer that Mr. Prosser read this paragraph, from the fact that he honors me by quoting from it, so that if for purposes of argument he calls the Guadalupian upper Permian, it is on his own responsibility, and he is liable to be called on to support the opinion, in which it is hoped the present work will be of some assistance.

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dAm. Jour, Sci., 4th ser., vol. 14, 1902, p. 363.
aProc. Washington Acad. Sci., vol. 7, 1905, p. 22.

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In the second of Mr. Prosser's premises he says that my lists of the Hueco fauna indicate that it is not related to any of the Kansas formations above the top of the Chase stage. From this he appears to infer that the Kansas "Permian" is younger than the Hueco formation, but in this case it is Mr. Prosser's inference that does not follow, for the Hueco fauna in some of its zones is so different from anything known in the Mississippi Valley that he would find it no easy task to show that the Kansas "Permian" is not represented there under a different faunal aspect. Besides, he seems to have overlooked the fact, at least once appearing in print,b that a gap, of undetermined though probably no very great extent, occurs between the highest known beds of the Hueco formation and the base of the Guadalupian. But supposing it to have been shown that the horizon of the Kansas "Permian" is in the upper part of the Hueco formation,c on its own merits one would be compelled to Class the "Permian" with the Hueco fauna, rather than with the Guadalupian, for I doubt very much whether Mr. Prosser would venture, on the strength of the faunal evidence now available, to trace much relationship between either the lowest fauna. of the Guadalupian (that of the basal black limestone) or the overlying Delaware Mountain sandstones and the Kansas "Permian." The third possibility, that of recognizing a Permian fauna of the Kansas type as an independent division, does not appeal to me at present with favor, but I shall refer to this point later.

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bBull. Univ. Texas Min. Survey, No. 9, 1904, pp. 35, 40.
cThe hypothesis in this case places its correlate above the highest known fauna of the Hueco, but presumably in what should be regarded as part of the same formation. Of course now and at all times the hypothesis is held in reserve that the two sections may have been more or less contemporaneous, though with very different faunas. Under those circumstances, however, it is in my judgment almost futile even to discuss their relationship on the strength of any evidence now in hand.

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In regard to the third stage of the argument, the passage which Mr. Prosser quotes from me as if it were a deduction from the two premises just passed in review really has no connection with his line of reasoning, and embodies a different meaning in the connection in which I wrote it from what is apparent in the connection in which he places it. The remaining half of the sentence quoted by Mr. Prosser, together with the context, is as follows: "If the Capitan fauna is 'Permian,' then certainly that of Kansas is not, for two Carboniferous faunas could scarcely have less in common. While it is possible that the so-called Kansas 'Permian' is a provincial phase of the Guadalupian, this is yet to be demonstrated, and it is questionable whether for two faunas so essentially unlike, even if proved to have been contemporaneous, the same name could with propriety be used." For my own part, I do not see how any other meaning can be drawn from these two sentences save that while I am not certain that the Kansas "Permian" may not have been contemporaneous with the Capitan, the two faunas are so different that the same name should not be applied to both. What I wished to state was that, the question whether Capitan time was contemporaneous with the time of deposition of the Kansas "Permian" being waived, the Capitan fauna is so different from the fauna of the Kansas "Permian" that the same name should not be applied to both. My discussion, in other words, had especially to do with terminology, while Mr. Prosser unfortunately makes it appear that I assert that if Capitan time was contemporaneous with the Permian epoch, then that of the Kansas beds was not, the faunas being so unlike. In point of fact I am ready to admit that two marine faunas may have a very different facies and still be contemporaneous. But at present I believe that the Capitan and the Kansas "Permian" were not contemporaneous, and that any two marine faunas differing as widely as the Guadalupian and the Kansas "Permian" should be distinguished by regional names.

Such investigations as I have made regarding the subject have left me positive on but few points. Two of these, however, have just been mentioned—that the Guadalupian fauna is entirely different from the Pennsylvanian and from the "Permian" of the Mississippi Valley, and that whether they are contemporaneous or not it would be a blunder to employ for both the same designation, either Permian or Guadalupian. Few will, I think, differ with me on these points. For the most part, however, I find myself seeing grave objections to the views maintained by others without being able to offer anything positive in the way of substitute, and entertaining a number of alternative hypotheses with no more than an opinion, more or less temporary, as to which the facts are likely to substantiate.

The two main points of Mr. Prosser's holding carry for me some serious difficulties, though while I can not yet accept them I do not wish to be understood as too positively maintaining opposite views. He finds the Kansas "Permian" fauna much more distinct from the underlying Pennsylvanian than appears to me warranted, and he correlates it too confidently with the Russian Permian. On neither point does it seem to me that very satisfactory evidence has been adduced. It is true that on the question of the Permian age of the Kansas beds he has canvassed professional opinion pretty extensively, and that at present the ayes seem to have it; but the ballot system, while not without value, has certain obvious shortcomings as a means of settling scientific questions.

I have never been able to see marked faunal changes in passing from the Pennsylvanian to the "Permian" of the Kansas section, and the lists which I prepared for Adams's bulletin on the Kansas formationsa do not indicate any important differences between the two. It is true that the lists are preliminary, and that their imperfections, failure on my own part to discriminate between related forms, and possible incorrect assignment by Mr. Adams of collections to one formation or another, would tend to obscure faunal changes which really exist; but on the whole I doubt if they seriously misrepresent the range of species or the facies of successive faunas. To me the Kansas faunal succession appears to be a gradually progressive one, modified of course by the passage of time and toward the end by the development of conditions which first banished or destroyed most of the brachiopod life and finally extinguished invertebrate life altogether. It is doubtful, if the question of the representation of the Permian in this country had never come up, whether the upper beds of the Kansas section would ever, on their merits, have been separated from the subjacent ones. The difference between the "Permian" and Pennsylvanian faunas of Kansas is to me by no means comparable to the difference between the Mississippian and Pennsylvanian faunas, but rather to the difference between some of the subdivisions of the Mississippian. Consequently, if the Kansas "Permian" really is Permian, then, so far as the facts are at present known and so far as this section is concerned, it appears to me doubtful whether more than two subdivisions are justified—the Mississippian and the Pennsylvanian—the "Permian" being no more than one of several members of the Pennsylvanian.

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aAdams, G. I., Bull. U. S. Geol. Survey No. 211, 1903, pp. 77 et seq.

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Regarding the correlation of the Kansas "Permian" with the Russian Permian I have not seen any very explicit or satisfactory statement of evidence. The question, it appears to me, should be considered both in the relation of the Kansas fauna and the Permian fauna as individual and detached in the relation of the entire faunal sequence of Kansas to the sequence of the Russian faunas; and, finally, in the relation of the collateral evidence which the faunas of other sections bring to the discussion.

The chief arguments which Mr. Prosser has advanced for the correlation seem to be these: The great development of Fusulina in the Russian section just below the Permian, paralleled by the development of the same group precedent to the "Permian" of the Kansas section; the development of Bakewellia in the Kansas Permian and the typical Permian of Russia; and the development in the same beds of the Pseudomonotis group of shells. As to Pseudomonotis, the genus was introduced in the Kansas section considerably before the "Permian." The abundance in which it occurs at about the horizon of the Kansas "Permian" appears to me a subordinate matter. Again, after critically examining the best specimens of Bakewellia which could be obtained I have been brought to entertain serious doubts as to their generic identity with the Bakewellias of the English Permian as represented in King's monograph. The dentition appears to be different and they seem to lack the characteristic series of external ligamentary pits.

It might also be pointed out that just below the Artinsk a zone in the Russian section is characterized by a profusion of Schwagerina occurring in association with Fusulinas. Now Schwagerina has never been reported from the Mississippi Valley, while I have recentlya offered reason for believing that the Fusulinas of the Kansas section, if they do not belong to a different genus, at least show important differences from the typical Fusulinas. These facts seem to destroy Mr. Prosser's argument so far as this item of evidence is concerned. At the same time these very forms furnish more stable evidence looking somewhat in the same direction.

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aAm. Jour. Sci., 4th ser., vol. 17, 1904, pp. 234-240.

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In a paper just received Mr. Yabe expresses the opinion that the generic term Trticites, which I introduced for the type of Fusulina found in the Mississippi Valley, is a synonym not of Fusulina but of Schwagerina It should be remarked at this point that Mr. Yabe regards Fusulina sensu stricto, Schwagerina, Doliolina, and Neoschwagerina as subgenera of Fusulina in the broad sense. With Mr. Yabe's opinion regarding the relationship between Schwagerina and Trticites I am disposed in the main to agree. When studying the Kansas Fusulinas I did not fail to consider the genus Schwagerina, but unfortunately employed Schwager's work on the Chinese Foraminifera as my authority relating to the genus which bears his name. Not having had the opportunity to examine the Asiatic species at first hand, nor having been led by my studies to more than a casual acquaintance with the literature of these difficult forms, I was unaware that Schwager had included two distinct types under Schwagerina, for one of which Schellwien had in 1897 introduced the name Möllerina, which he subsequently (in 1902) changed to Doliolina, I saw that Trticites differed widely from the Doliolina structure, which has its inception in the basal skeleton of the Chinese Schwagerinas, and concluded that the two were distinct. Nor did I fail to note that Trticites did not differ greatly from our western Schwagerinas (e. g., Schwagerina robusta of California), but the inference from this naturally was (still using Schwager's Schwagerina as a point of departure), not that Triticites was a Schwagerina, but that the western Schwagerina was not a true representative of the genus, but more probably related to Triticites. With the misleading Doliolina craticulifera removed, Triticites becomes very closely similar to Schwagerina.

As the case now stands, therefore, with the Kansas form cited under Schwagerina there appears to be some authority for correlating the upper part of the Kansas section with the Schwagerina zone of Russia. On this basis, however, the beds above would correlate not with the Permian but with the Artinsk, and the propriety might legitimately be impugned of separating on internal evidence the beds overlying the abundant occurrence of Schwagerina in the Kansas section and of correlating them with the Artinsk rather than assigning to the Artinsk some of the nonfossiliferous beds still higher in occurrence, since the rather thin series above the Schwagerina horizons (for the genus ranges practically throughout the Kansas section) neither shows any great difference from the fauna below nor any marked affinity with the fauna of the Artinsk or Permian, while the higher nonfossiliferous horizons at least have the virtue of potentiality in the way of convincing evidence. After all, the evidence created by the transfer of the Kansas Fusulinas to Schwagerina is not very strong, and Mr. Prosser's argument is retroactive, since if the beds below the Russian Permian are so characterized by the abundance of Fusulina the total absence of this genus (now Schwagerina) in the Kansas section may not be without its significance, while the Kansas Schwagerinas certainly belong to a distinct group from the typical ones, whose zone is below the Artinsk, the Kansas forms being distinguished by their fusiform instead of globular shape, their thickened instead of slender septa, and the absence of any trace of a basal skeleton.

Anyone acquainted with the Carboniferous faunas of Kansas who examines Geinitz's work on the Dyas must be struck by the resemblance between the American and the German faunas. It is this resemblance probably which led Geinitz to correlate the two, but the Dyas is not the Russian Permian, though doubtless closely allied to it, and the American fauna which it especially resembles is not Mr. Prosser's Permian, but an antecedent one. Of course, a fortiori, if the underlying beds are Dyas the Kansas "Permian" is Permian if the Dyas is Permian; but at the same time the resemblance indicates what has already been stated as my opinion—that no marked break divides the Kansas "Permian" from the Pennsylvanian, and that if the former is to be correlated with the Russian Permian there is no reason why an indefinite thickness of the underlying measures should not be considered Permian also, and no reason why the "Permian" in Kansas should be distinguished as a separate system or epoch ranking with the Mississippian.

The relationship between the Dyas and the Kansas faunas lies chiefly in the pelecypods, the Bryozoa and the Gasteropoda showing somewhat less important resemblances. The latter group especially is apt to furnish rather unsatisfactory correlative evidence, since generic characters of the first importance are not preserved in the Paleozoic at all and the minor generic characters are frequently destroyed or concealed. Comparisons, therefore, have often to be made with uncertainty as to whether forms do or do not belong to the same genus, and depend not infrequently on rather superficial or subordinate characters.

Even among the pelecypods, however, one can not but observe some noteworthy differences, such as the presence in the German fauna of Liebea hausmanni, Plagiostoma permiana. and several species of Bakewellia doubtfully congeneric with Bakewellia parva of the Kansas "Permian". Other points might also be noted, such as the abundance of Chiton in the Dyas, but in the main the resemblance is certainly striking. It is important to observe, however, that the resemblance is not restricted to the higher faunas of the Kansas section, but continues to exist when the earlier Pennsylvanian horizons of the Mississippi and Ohio valleys are held in view.

The most marked differences, however, are to be found among the Brachiopoda, a group which is of special importance because of their general abundance and good preservation, the precision with which genera can be determined, and often the relatively brief range of specific and generic types.a The Brachiopoda of the Kansas "Permian" are survivals of those of a previous horizon, and they are very different from the brachiopods of the Dyas. There is nothing in the entire Kansas section to compare with the Dyas species of Streptorhynchus, Productus (P. horridus, P. latirostratus, P. geinitzianus, P. hemisphaerium, and P. robertianus), Strophalosia, Spirifer (S. curvirostris and S. schrenki) and Camarophoria. Some of the types mentioned appear to be abundant in and characteristic of the Dyas, so that the Brachiopoda of the two faunas appear to contain wide and important differences. The types which are held in common date from an earlier stage in both areas and have an almost world-wide distribution.

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aThis is, I am aware, contrary to what has often been maintained, but it seems to me that in the Carboniferous at least genera and species of brachiopods are distinguished on more valid and better established data, and they have a briefer range, than other groups.

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In Tschernyschew's account of a Permian fauna from Kostroma there are few striking differences when compared with the Kansas "Permian," and most of these occur among the brachiopods, such as Camarophoria, Strophalosia, and Aulosteges, genera not known in the Kansas section. The resemblances, however, are not especially with the Kansas "Permian," but rather the reverse, and consist of types which range well down in the Pennsylvanian section. Much the same is true of the Permian fauna described by Golowkinsky. The greatest differences here are shown among the Brachiopoda (Strophalosia horrescens, Productus cancrini, P. hemisphaerium, and Spirifer rugulatus); but the resemblances are by no means with the Kansas "Permian" as distinct from the Pennsylvanian. Also, in the extensive Permian fauna described by Netschajew, aside from the Brachiopoda, which are for the most part very unlike any phase of the Kansas faunas, there are few marked differences which can be pointed out. One important exception, however, consists of the Permian Anthracosias (Palaeomutela, Oligodon, Naiadites, and Anthracosia), of which Netschajew cites 40 species. Amalitzky distinguishes 60 species of this group, which is, so far as known, entirely absent from the Kansas series. In this case also the resemblances do not point to a relationship between the Russian Permian and that of Kansas as distinguished from the Kansas Pennsylvanian, but appear to be equally great with the latter. I would not, however, interpret this to indicate that the Kansas "Permian" is younger than the Russian Permian. The Kansas "Permian" appears to me to represent the last stage of a fauna which was being somewhat modified, indeed gradually annihilated, by conditions which were adverse to it. The meager representation of the final stages naturally affords a less satisfactory basis for comparison with the highly differentiated Russian Permian (Netschajew cites 249 species of invertebrates), presenting fewer points of resemblance and more points of negative difference.

I have, however, considered only the features in which the Russian Permian fauna differs from the Kansas "Permian," and even in this rapid and very general survey have neglected a number of instances which are worthy of notice. A more critical and detailed comparison of the two faunas would, I venture to say, still more increase the sum of difference. Nor have I considered elements in the Kansas "Permian" which are absent from the Russian Permian. On the intrinsic characters of the two faunas it seems to me that no more than a very provisional correlations is justified.

The paleobotanical evidence which has recently been brought forwarda to identify as Permian part of the Kansas section is not unimportant, but if I may do so without appearing to try to prove that the Kansas beds are not Permian, rather than merely to examine critically the evidence for believing that they are, I would point out several considerations in relation to this line of evidence. In the first place, here and elsewhere in speaking of the Kansas "Permian" I refer to the Chase and Marion formations, but not to any of the higher beds, as I believe that the only practical method of correlating terranes so widely separated as those of Kansas and Russia is by paleontologic evidence; and since the evidence of invertebrate paleontology only is that which I am in a position to understand and weigh, it is natural that any statement of mine must apply to that portion of the Kansas section where invertebrate fossils are found, and can not consistently apply to formations overlying the Marion, where invertebrate evidence appears to be absent. Furthermore, unless otherwise indicated, in speaking of the Permian I refer primarily to the Russian Permian exclusive of the underlying Artinsk or "Permo-Carboniferous."

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aKansas Univ. Quart., vol. 9, 1900, pp. 63, 64, 180-189; vol. 10, 1901, pp. 1-12; Trans. Kansas Acad. Sci., vol. 17, 1901, pp. 208, 209.

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Now, regarding the plant evidence, it appears that the horizon from which it was obtained is not as yet definitely fixed, but is regarded as being at the top of the Marion or the base of the Wellington, or, in other words, in the highest strata of the Kansas "Permian" if not above that series. On the other hand, the correlation by paleobotany is not with the Russian Permian but with the German, and not with the Zechstein, whose fauna seems most to resemble the typical Permian, but with the Rothliegende, which underlies it and may belong to a different epoch.

It is instructive to compare the entire series of Russian faunas with that found in Kansas in its bearing on the age of the Kansas "Permian." Whoever examines Trautschold's monograph on the Moskovian, the lowest terrane of the Russian Carboniferous above the Mountain limestone, must be struck by its resemblance to the ordinary Kansas fauna. The resemblance is to the Pennsylvanian of Kansas, however, rather than to the "Permian," but, as I see it, the Kansas "Permian" differs from the lower beds more by elimination than by any positive qualities. The Gschelian, the next succeeding fauna of the Russian section, shows considerable that is different from the Moskovian, and it varies widely from the Kansas faunas as a whole or from the fauna of any particular bed in the section. If 50 Gschelian species were found in the Mississippi Valley, probably 49 of them would be recognized as new and the whole as constituting a fauna having a facies widely different not only from anything in Kansas but also from anything in eastern North America, so far as known. In my judgment the difference between the Gschelian fauna and any of the Kansas faunas is far greater than that between the Kansas "Permian" and the underlying Pennsylvanian. A thoughtful inspection of Tschernyschew's monograph on the Gschelian Brachiopoda will, I am convinced, bear out this statement. The Artinskian fauna, most interesting on account of its ammonoids, but otherwise rather closely allied to the Gschelian so far as I could make out from the literature, is also unrepresented in Kansas. Above the Artinsk is the Russian Permian, which we are told is equivalent to the "Permian" of Kansas.

No one would seriously hypothetize a gap between the Pennsylvanian and "Permian" of Kansas during which the Gschelian and Artinskian beds were being put down. The alternative hypothesis is that, while comparable at first, the Russian faunas went through very different metamorphoses, the American faunas remaining more nearly uniform, and both concluding in a similar vein. This hypothesis would also account for the important differences which seem to me to exist between the Russian Permian and that of Kansas, but if the differences are admitted the particular difficulty making need for the hypothesis is eliminated.

It is necessary finally to consider the evidence which a few other faunas contribute to this question. That which Beede obtained from the red beds of Oklahomaa is too scanty to prove more than that Carboniferous faunas extended considerably higher into the red beds than is shown by the Kansas section. The beds at Whitehorse Springs are, I believe, supposed to be several hundred feet above the top of the Marion. Their limited fauna is related to that of the Kansas "Permian," but shows at the same time some differences suggestive of a different and younger facies. The differences from the Kansas "Permian," however, are not resemblances to the Russian Permian, the close relationship to which of either fauna seems to me rather questionable.

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aBeede, J. W., Am. Geologist, vol. 28, 1901, pp. 46-47; Adv. Bull. First Bien. Rept. Okla. Geol. Survey, 1902, 9 pp.

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The ammonoid fauna of Texas appears to be related not to the Russian Permian, to which period American writers have usually assigned it, but to the Artinsk. This fauna does not occur in the Kansas section. The position there of the Wichita is not definitely known. I have imagined it to be no older than the Kansas "Permian," and possibly younger.b This would make the "Permian" of the Kansas section, if not older than the Artinsk, older than the Russian Permian. Tschernyschew correlates part but not all of Prosser's "Permian" with the Artinsk. Prosser's extension of the term "Permian" to cover the Marion, if this correlation is correct, is quite justified by the precedent of some of the Russian geologists, who include the Artinsk in the Permian, as previously noted. This does not, in my view, constitute the best usage, for, as I understand the matter, the Permian as originally defined did not include the Artinsk, and there is no peremptory faunal evidence demanding a departure from the original meaning. On the basis of this doubtful correlation it would appear that even the Marion is older than the typical Permian.

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bCummins states (Trans. Texas Acad. Sci., vol. 2, 1897, p. 98) that the upper portion of the Wichita division of Texas in which White's ammonoid fauna was found is the same as the Fort Riley horizon of Kansas, whose position is in the middle of the Chase group.

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The faunas of the trans-Pecos section also bear on the present question, for in some of them I believe there can be traced a distinct relationship with some of those of the Russian section, while it is possible if not to determine at least to approximate the stratigraphic relationship which they bear to the Kansas section. As stated in my recent paper,c the fauna of the Hueco formation which underlies the Guadalupian, appears to me closely related to the Russian Gschelian, while a different fauna which lies below the Hueconian may tentatively be correlated with the Moskovian stage. The ammonoids of the lower Guadalupian are very suggestive of the Artinsk, but aside from this I must confess that there appear but broken analogies between the Guadalupian and the Artinskian or the Permian. Faunally the Guadalupian is quite unlike any of the faunas of eastern North America. The Hueco fauna, though still considerably different, shows decidedly greater resemblance to the Kansas faunas, while the faunas beneath the Hueco are perhaps least different of all. To trace the trans-Pecos section into the Mississippi Valley by the south is at present impossible. In passing northward it appears that the Hueco beds, typically consisting of dark limestones, change their color and lithology, and are represented by red beds interspersed with limestones. In the Grand Canyon section they appear as the Aubrey sandstone and limestone, while in Utah the Weber quartzite seems to be equivalent to them. These correlations are at present provisional. With still greater reserve are the red-beds faunas of Wyoming correlated with the Weber on the one hand and the upper part of the Kansas section on the other. Their relationship with the eastern fauna is far stronger than with the western. At present I see no evidence of their being younger than the Weber, but they may be older. Conservatively they may be placed in the same epoch. If we accept this correlation of the Hueco formation with the Gschelian on the one hand and the Kansas Carboniferous on the other, the Guadalupian would consequently correspond to the Artinsk or to the Artinsk and the Permian. This would agree with the correlations of some European writers, for the Guadalupian fauna is more nearly related to that of the Fusulina limestone of Palermo than to any other European fauna, and the Sicilian beds are correlated with the Artinsk by some writers or with the Permian by others. Or, if, as Prosser claims, we assume that the upper part of the Kansas section is younger than the Hueco formation, or the known fossiliferous portion of it, it would follow, if the Kansas "Permian" is Artinsk, as Tschernyschew believes,a that the Guadalupian is presumably Permian; but in this case the difference between the faunas of the Kansas "Permian" and any part of the Guadalupian is so great that in North America at least the Guadalupian as Permian must be sharply distinguished from the Kansas "Permian" as Artinsk, and the course adopted by some geologists of uniting both divisions under the Permian would not answer for the North American series. The relationship between the fauna of the Kansas "Permian" and those of the underlying beds is so close that the Kansas "Permian" as Artinsk would have to be regarded as forming a part of the Pennsylvanian.

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cProc. Washington Acad. Sci., vol. 7, 1905, p. 20.
aMém. Com. géol., St. Petersburg, vol. 16, No. 2, 1902, pp. 395, 706.

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Or, if we still assign the Kansas "Permian" to a position above the known faunas of the Hueco formation though presumably below the Guadalupian, but suppose it now to be equivalent not to the Artinsk but to the Permian of the Russian section, then it must follow that, if not strictly all, at any rate most of the Guadalupian series is a new group younger than the Permian. This does not seem at first sight at all probable, and yet on deeper consideration it is not entirely impossible.

It does not seem to me necessary to regard the Russian Permian as the last chapter in the Paleozoic history. Apparent gradation is a dangerous criterion in determining whether sedimentation was continuous, since an encroaching sea reworking the detritus of much older deposits could and apparently sometimes does form to the eye continuous series of sediments. Faunally the Permian does not seem to me to be at all strongly suggestive of the Mesozoic, but to be distinctly Paleozoic in its facies. The coelenterates, the echinoderms, the bryozoans, the brachiopods, the pelecypods, and, less strikingly, the gasteropods and cephalopods (including those of the Artinsk) are in my view distinctly Paleozoic, with but slight inclination to the Mesozoic facies. The decline of the brachiopods in the Permian has sometimes been cited as foreshadowing the advent of the Mesozoic, but brachiopods are abundant in the lower Mesozoic of Europe, and the groups which are being extinguished in the Permian are the wrong ones for this deduction. The types especially differentiated in the Mesozoic are the Rhynchonellas, the Spiriferinas, the Terebratulas, and the Thecidiidae. These four groups are rather notable in the Permian by the poverty of their development, the most abundant forms being apparently the distinctly Paleozoic strophomenoids and productoids. In the faunas of Palermo and of the Guadalupe Mountains the strophomenoids and productoids are also well developed, but the Rhynchonellas, the Spiriferinas, and the Terebratulas are differentiated to a high degree and thus contain an intimation of the Mesozoic. Other similar features could be noted wherein these faunas more than the Permian appear to be anticipatory of the subsequent epoch. Finally, the important differences in facies which are shown by the faunas of Palermo and the Guadalupe Mountains when compared with the Permian may indicate differences in age almost as much as differences in environment. In closing this argument, however, I may say that I have elaborated it not so much because I believe that the relations are so, as because I believe that they may be so, from which perhaps it will be gathered that the measure of my credence is rather large.

Thus far I have considered the relations which would exist if the Kansas section were equivalent to the Hueco formation. That it overlies the Hueco formation seems at present, from data in hand, too little likely to engage discussion. Less improbable is it that the Kansas beds underlie the Hueco. In the light of the present insufficiency of facts or supposed facts this hypothesis is not without substantiatory evidence. We have the facies of the Hueconian fauna different from but related to that of the Kansas beds, a relationship which lends itself to the interpretation of being due to succession in time as well as to a contemporaneous but different environment. There is evidence for believing that the Hueconian is a red-beds fauna, in spite of the different lithology of the typical section. A series of beds below those carrying the typical Hueco fauna have an assemblage of forms much more like the Pennsylvanian than the Hueco fauna itself—that is, it has fewer non-Pennsylvanian types. Thus we have in each area a group of rocks with like faunas followed by a series of red beds of Carboniferous age. The red beds of the Kansas section are unfossiliferous, save for the fauna from Oklahoma, which Beede described and which is not very distinctive. The Hueco fauna consists largely of brachiopods and gasteropods, and so is out of touch with that from Oklahoma. Perhaps the most noticeable feature of the latter is the Dielasma, distinct from the Pennsylvanian Dielasmas and rather suggestive of the western types. This hypothesis also makes the Mississippi Valley faunal sequence analogous to that of Russia. The Kansas beds and pre-Hueconian beds would correspond to the Moskovian in faunal aspect, the Kansas red beds and the Hueco formation to the Gschelian, and the Guadalupian to the Artinsk and Permian. Of course in this case the Kansas "Permian" could be no younger than the Gschelian.

While this hypothesis should not be overlooked, it seems to me more probable that the upper Carboniferous of the Mississippi Valley represents not the pre-Hueconian alone of the trans-Pecos and New Mexico section, but the pre-Guadalupian as a whole, the eastern faunas having remained almost uniform throughout, but the western faunas having in the latter half of the period represented taken on a new facies. Whether the enrichment of the fauna during this epoch was by differentiation or by immigration I do not see any way of determining, nor, in the latter event, whether the migration was from America to Asia, from Asia to America, or to both from a third region.

It remains to express the heavy obligations under which I stand to various friends and colleagues in the preparation of this report. As the work, owing to frequent and prolonged interruptions, has extended through several years, some acts of kindness and of aid have probably been overlooked. I have frequently advised with Mr. Charles Schuchert and Mr. R. S. Bassler on scientific points and with Mr. T. W. Stanton, Mr. David White, and Mr. G. B. Richardson on more general matters. I have also on several occasions consulted Mr. E. O. Ulrich. Dr. J. H. Britts, of Clinton, Mo., kindly loaned me some specimens collected and identified by the Shumards. To all these gentlemen my sincerest thanks are extended. To the United States National Museum I am, as always, indebted for facilities and for the use of specimens, partly as the subject-matter of this paper and partly for purposes of comparison. Nor am I forgetful of those whose efforts contributed to build up the collections which form the basis of the investigations here reported—Mr. R. T. Hill, Mr. G. B. Richardson, Mr. B. F. Hill, and Mr. E. H. Elder.

Range and distribution of the Guadalupian species.

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