Geological Survey Professional Paper 58 The Guadalupian Fauna

CŒLENTERATA.

The Guadalupian corals are inferior in interest to the other groups. The genera recognized are Lindstrœmia, Zaphrentis, Amplexus, Campophyllum, Cladopora, and Aulopora. Most of these types range upward from much earlier horizons, and in the case of Cladopora this is, I believe, the first recorded occurrence at so late a period. Nevertheless, the Guadalupian Cladoporas, in one instance at least, afford no adequate ground in my opinion for separating them from the earlier types.

Certain genera which Waagen and Wentzel included with the cœlenterates but which I would place with the Bryozoa being omitted, the corals of the Salt Range fauna include Aræopora, Pachypora, Michelinia, Lonsdaleia, Amplexus, Carterina, Disjectopora, Irregulatopora, and Circopora, comprising in all 19 species. The corals would therefore seem to be not only far better represented in the Salt Range fauna, but to have largely a different character. The genus Amplexus is all that our lists show the faunas to have in common, although it is possible that the forms which Waagen and Wentzel have referred to Pachypora and those which I have placed with Cladopora may be congeneric. An interesting feature of the Salt Range fauna consists in the development of certain stromatoporoid corals belonging to four new genera. All these types are quite foreign to the co&elig;lenterate representation found in the Guadalupian, though some of Waagen's and Wentzel's figures are certainly strongly suggestive of the sponges rather than of the cœlenterates. It is singular that these authors should have selected the specific name placenta for one of their species of Michelinia, as the name was preoccupied by an American species, although now the latter is placed with the genus Leptopora.

In his first paper on the Chitichun fauna No. 1 Diener cites a species of Amplexus and one of Lonsdaleia, and in his later paper on the same fauna a species of Amplexus, one of Zaphrentis, one of Clisiophyllum, one of Dibunophyllum, and one of Plerophyllum. It is evident that the cœlenterates of the Salt Range and of the Himalaya are not closely allied to those of the Guadalupian.

Kayser cites only two varieties of Lophophyllum and a species of Michelinia from the Carboniferous fauna of Lo Ping. From the neighborhood of Kantschoufu Loczy mentions an undetermined species of Hallia, from the neighborhood of Batang an undetermined species of Lonsdaleia, from Talischau in the province of Yunnan a species of Favosites and one of Hallia?, and from Youngtschangfu a species of Zaphrentis. The Carboniferous faunas of China also, so far as known, would appear from this to show no very close relationship with the Guadalupian.

Beyrich's corals from Timor afford more analogies with the Guadalupian than almost any other fauna. Among the forms distinguished by him there belong to this group certainly three species—Zaphrentis? sp., Cyathophyllum? sp., and Clisiophyllum australe. The latter species particularly recalls the forms which I have placed with Lindstrœmia. A fourth form, which Beyrich calls Calamopora sp., appears to have too large cells for a bryozoan and strongly suggests the Guadalupian species which I have cited under Cladopora. Martin cites from Timor a number of species of corals belonging perhaps to several faunas. These comprise a new species of Lophophyllum, three varieties of Lithostrotion, a species of Favosites, and one of Amplexus, a co&elig;lenterate group certainly not closely allied to that from the Guadalupe Mountains. Rothpletz, in describing the faunas of Timor and Rotti, distinguishes a considerable list of species, including the genera Pachypora (2 species, one of which will perhaps prove to be a bryozoan), Polycœlia (1 species), Zaphrentis (1 species), Amplexus (2 species), Dibunophyllum (1 species), and Clisiophyllum (4 species). A certain resemblance to the Guadalupian fauna is shown, which may be increased by the possibility that the forms which I have placed with Lindstrœmia and those referred by Rothpletz to Clisiophyllum are in some cases congeneric; but at all events the resemblance is not close.

Roemer cites a species of Clisiophyllum and one of Lithostrotion from Sumatra and Fliegel a species of Clisiophyllum and one of Lonsdaleia from Padang.

In the Russian section corals appear more or less abundantly in every division, and persist into the Permian, where Netschajew cites Petraia (1 species), Zaphrentis (2 species), Polycœlia (1 species), and an undetermined form. Probably this representation could be much augmented by collating different lists, and really large numbers of species names could be gathered from other horizons in the same manner. Among works in which fossils of this group are described and figured, that by Trautschold on the fauna of Mjatschkowa contains representation of a good many species. Stuckenberg's monograph on the corals and Bryozoa of the Russian Kohlenkalk treats of still more. Netschajew's work on the Permian contains a few others, as already noted, and so does the monograph by Murchison, De Verneuil, and Keyserling; but in no case is any special resemblance to the corals of the Guadalupian manifested, so that to consider the matter in detail would be unprofitable as well as laborious. Some comment on the genus Chætaetes, however, will not be out of place, for it is a form readily determinable and in many places abundant. Stuckenberg records three species in the upper Kohlenkalk of middle Russia, Trautschold two species in the Moskovian, and Stuckenberg one in the Gschelian. In his monograph on the Gschelian Brachiopoda, Tschernyschew also cites Chætaetes at that horizon. The absence of this genus from the Guadalupian seems to establish a difference between it and the lower formations of the Russian section and an agreement with the Artinskian and Permian, where it appears to be absent.

Abich recognizes 5 species of Amplexus, 2 of Clisiophyllum, 2 of Zaphrentis, 1 of Lophophyllum, and 1 of Michelinia in his fauna from Djoulfa, in Armenia, an assemblage which certainly possesses little in common with that of the Guadalupe Mountains. Arthaber, who subsequently worked over much the same fauna, discriminated Amplexus (1 species), Zaphrentis (1 species), Favosites (1 species), and Michelinia (1 species).

In the fauna from Balia Maaden, in Asia Minor, Enderle found only 2 species of Lonsdaleia and 1 of Amplexus.

I do not know whether Gemmellaro published an account of the corals belonging to the fauna from Palermo, but if so I have been unable to examine a copy of his work; nor have I been able to find whether Schellwien has described this group as it appears in the fauna of the Trogkofelschichten.

Gortani has noted a few corals from the Carnic Alps which he refers to the genera Zaphrentis (1 species), Cyathophyllum (1 species), Monilipora (1 species), and Syringopora (1 species). We apparently shall not find here any close analogy with the Guadalupian cœlenterates.

The Dyas of Germany would appear to contain merely Calophyllum (or Polycœlia) profundum and a doubtful Dingeria depressa.

The corals of the Permian of England seem to be equally scanty. King cites Calophyllum donatianum and Petraia profunda.

In the Spitzbergen fauna likewise the corals play a subordinate part, but Toula cites two species of Clisiophyllum from the cape between the two arms of North Fjord. Among the Nova Zembla fossils this author cites 1 species of Campophyllum, 1 of Zaphrentis, 3 of Lithostrotion, 1 of Michelinia, 1 of Chætaetes, and 1 of Clisiophyllum.

Stache cites a number of species from localities in the West Sahara, but they are of different genera from the Guadalupian types (Favosites, Cyathophyllum, Hadrophyllum?, Amplexus?, and Duncania?), and for the most part probably belong to an older fauna.

The "Permo-Carboniferous" beds of Queensland and New Guinea contain according to Etheridge, only a few corals—Zaphrentis (1 species), Cyathophyllum (2 species), and Cladochonus (1 species)—a rather meager and characterless list, but one which, as far as it goes, is quite different from the Guadalupian.

De Koninck's account of the Carboniferous fossils of New South Wales contains descriptions of an extensive suite of corals, viz, Axophyllum? (1 species), Lithostrotion (2 species), Cyathophyllum (1 species), Lophophyllum (2 species), Amplexus (1 species), Zaphrentis (4 species), Cyathaxonia (1 species), Cladochonus (1 species), Syringopora (2 species), and Favosites (1 species). This list seems to indicate a more primitive facies than the Guadalupian, and certainly a very different one. From the associated data I judge that all were obtained from the lower beds of the Australian section, and it would accordingly not be to the purpose to consider them further here. Syringopora reticulata appears to be cited from the upper as well as the lower beds and to form an exception to the first part of the preceding remark but not to the last.

The only coral which I have found noted from the Carboniferous of South America is from Bolivia. D'Orbigny cites Turbinolia striata, a zaphrentoid species which will have to be redescribed before one can tell much about it.

The Guadalupian corals, so far as they are known, contribute but little toward endowing the fauna with an individual or novel character, and yet they do not manifest any marked affinities with the other faunas with which comparisons have been made.

The coral fauna of the Pennsylvanian is much less extensive than that of the Mississippian. According to Weller's bibliography, the western forms, as usual, being rejected, the Pennsylvanian comprises only the following species:

Of these, Campophyllum, Lophophyllum, and Chætaetes are perhaps the most abundant and characteristic. If the list of Guadalupian species be compared with this it will appear that the generic representation of the corals is very different in the two faunas, that they have in fact only two genera in common—Campophyllum and Zaphrentis—while the Guadalupian forms doubtfully placed with Campophyllum are very different from the common Pennsylvanian Campophyllum torquium. I am satisfied that Lindstrœmia permiana is not congeneric with the characteristic Pennsylvanian species Lophophyllum profundum, nor does it belong to Axophyllum, which includes another Pennsylvanian species. Thus it would seem that in its corals, not less than in the other groups, is the Guadalupian fauna different from the Pennsylvanian.

TETRACORALLA.

Family ZAPHRENTIDÆ Milne-Edwards and Haime.

Genus LINDSTRŒMIA Nicholson.

LINDSTRŒMIA PERMIANA n. sp.

Pl. XVII, figs. 13 and 14.

?1859. Polycœlia(?). Shumard, Trans. Acad. Sci. St. Louis, vol. 1, p. 388 (date of volume, 1860). Dark [Permian] limestone: Guadalupe Mountains.

Corallum of medium size, conical, gently curved, varying somewhat in the rapidity of its expansion, which is seldom either unusually rapid or unusually gradual. The exterior is sometimes marked by constrictions due to unequal growth and by numerous rather regular longitudinal ribs or ridges, the distinctness of which varies in different specimens. They are usually rather faint. These are grouped in such a way that the periphery is divided into three unequal parts. One longitudinal line of division, formed by the convergence of the ribs, is situated on the concave side of the corallum and the two others are about 90° of arc from it.

In estimated length the largest specimens probably do not exceed 40 mm., while the greatest diameter is about 18 mm.

The calice is very deep; the septa are numerous and closely arranged and number from 48 to 56, of which half are primary and half secondary. This relation, however, is seldom apparent except in the calice, where sometimes the septa are regularly alternating, and in special instances in the lower part of the epitheca. The septa for the most part extend to the center and unite in a pseudocolumella. The pseudocolumella is large when compared with that of Lophophyllum, but it is small when compared with the corresponding structure in Axophyllum. It appears not to be solid like that of Lophophyllum, but to consist of the interlocked ends of some of the septa. It often has the aspect of being solid, however, because the interstices are filled with a stereoplasmic deposit. I am uncertain about the existence of a fossette. In some specimens such a structure appears to be present (by the atrophy of one or two of the septa) and in others not; at all events it is not conspicuous. If it does exist it seems to bear no relation to the curvature of the corallum. Dissepimental tissue is present in moderate abundance, but tabulæ are absent. In longitudinal sections the dissepiments are seen to ascend steeply to the pseudocolumella.

Considerable variation is shown by coralla referred to this species. In some specimens the longitudinal striæ are much less distinct than in others, and, correspondingly, the annular striæ and constrictions are much more pronounced in some. The difference in expansion has also been a subject of comment, and this exercises an influence on the internal as well as the external appearance, for since the number of septa remains fairly constant their arrangement in the narrow forms is more crowded than in the spreading forms. A difference in silicified specimens in the extension toward the center of septa in the calicecan in some cases be definitely ascribed to the fact that their inner extremities were not silicified. The length of the secondary septa also varies, as well as their arrangement, since they are occasionally situated to one side of the interseptal spaces or are bent over to unite with the principal septa.

In the calice, which is floored by dissepimental tissue, even the primary septa do not extend to the pseudocolumella, but at lower levels, as shown by sections, they extend to and unite with it.

In young specimens referred to this species the number of septa is proportionally less, according to their size, and the secondary septa proportionally smaller.

This species appears to be represented at several different horizons and at a number of localities. While the sum total of specimens is considerable, not many have been obtained at any one station. Therefore in considering the material as a whole, the danger that it may not all belong to the same species is somewhat increased. Many of the specimens are fragmentary and the preservation is unsatisfactory. In but few instances do these fossils retain their original calcareous composition. In most cases they are silicified, but sometimes, as in the "dark limestone," the silicification, while sufficient to render sectioning laborious and unsatisfactory, is not complete enough to give a faithful replacement of the original body, while sometimes, as in the Glass Mountains, the matrix also is highly siliceous, so that etching does not serve to free the corallum. Thus all the characters described can not be made out on any one specimen, and the danger resulting from a confusion of more than a single species becomes more grave. However, this circumstance has been kept in view and care taken to avoid error as far as possible.

Of the generic position of this form I am somewhat in doubt. It can hardly be referred to Axophyllum and appears in fact much more nearly allied to Lophophyllum. The fact that the columella is composite, not simple and solid, and that it is connected with many of the septa, perhaps sometimes with all of them, seems to debar that genus also. The presence of dissepiments is likewise a distinguishing character of some value, though I have found that Lophophyllum possesses these structures, contrary to many descriptions of the genus. The development in Lophophyllum, however, is always scanty.

The paper in which the name Lindstrœmia was first proposed was published as an abstract, and I have not come upon a subsequent characterization of the genus, though Nicholson discusses it at some length in his manual of paleontology. The original abstract, however, contains a rather full generic diagnosis, which can be supplemented by the remarks contained in the manual. With the first description the Guadalupian form agrees in most particulars. The chief points of divergence seem to be that the diagnosis calls for a small coral, while this species, though small in comparison with many Devonian and even some Carboniferous species, is near the average of Carboniferous forms. Neither can it be said of the pseudocolumella, though it is relatively larger than that of Lophophyllum, that it occupies a large portion of the visceral chamber. These differences can, it is true, hardly be regarded as generic, but it is possible that in structures not described in detail by Nicholson, especially that of the columella, differential characters would be found. Furthermore, the type species of Lindstrœmia (L. columnaris) is a Devonian fossil and the genus is reported by Nicholson as being especially abundant in the Ordovician and Silurian rocks, though he notes finding it in the Carboniferous also. In the manual of paleontology above referred to Nicholson gives some additional characters which have a bearing on the generic reference of the present species. He remarks that the septa are pinnate in their arrangement and that the symmetry is bilateral, though a fossula seems not to be present. It has already been said that a certain trimeral arrangement of the external ridges has been observed in the Guadalupian form, though I doubt if all the specimens show even this, and no such arrangement is apparent in the interior, where a general radial symmetry prevails. As already stated, there is some uncertainty about the possession of a fossula by the Guadalupian form, and I believe that a structure of this nature is not a constant feature. In this character it is apparently in agreement with Lindstrœmia. While the maximum development of the genus, as recorded by Nicholson, is much earlier than the present occurrence, the fact that Waagen has found corals such as Michelinia, and stromatoporoids, in the "Permo-Carboniferous" of India, affords some sort of a precedent for extending the range of Lindstrœmia to the Guadalupian beds of Texas and New Mexico.

Horizon and locality.—Middle of Capitan formation, Capitan Peak (station 2926); "dark limestone," Pine Spring (station 2930), and Guadalupe Point (station 3762b?); Delaware Mountain formation, Guadalupe Point (station 2919?), Guadalupe Mountains, Texas. Delaware Mountain formation, southern Delaware Mountains, Texas (stations 2964?, 2969?, 3500). Delaware Mountain formation, Diablo Mountains, Texas, as reported (station 3764). Delaware Mountain formation, Comanche Canyon, Glass Mountains, Texas (station 3763).

LINDSTRŒMIA PERMIANA var.

Pl. XVII, fig. 15.

Associated with the typical Lindstrœmia permiana is a form resembling it in a general way but possessing this obvious difference, that it is smaller and has somewhat fewer septa. The difference in size seems to me not such but that coralla belonging to L. permiana would have had more numerous septa when of similar dimensions. The number of primary septa in this form is 19 or 20, the total number of septa in a corallum being, therefore, 38 or 40. It hardly seemed justifiable to place these fossils immediately with L. permiana, and at the same time the difference does not at present seem sufficiently important to warrant proposing a new name for them.

Horizon and locality.—"Dark limestone," Pine Spring (station 2930) and Guadalupe Point (stations 3762e?, 3762d), Guadalupe Mountains, Texas. Delaware Mountain formation, southern Delaware Mountains, Texas (stations 2968 and 2969).

LINDSTRŒMIA CYLINDRICA n. sp.

Pl. XVII, figs. 16 and 16a.

Corallum rather small, subcylindrical, strongly curved. The entire length is 23 mm., the diameter at the aperture 8 mm. When the typical specimen had reached a length of 11 mm. it had nearly attained its full diameter and was a straight cone. The remaining growth was in shape cylindrical and in a different direction from the original one. The external surface is marked by distinct longitudinal ribs and by rather prominent transverse bands, due to irregular and interrupted growth. The calice is rather deep, but not so deep as often seen in Lindstrœmia permiana. It contains 16 septa, all of which are primary. No secondary septa appear. In the calice the septa do not extend to the center, the unoccupied space between their inner ends being floored by dissepimental tissue, from the midst of which the rather small, low pseudocolumella projects. A similar appearance has been observed in L. permiana also, but it is probably misleading as to the real structure beneath, and is doubtless calicinal in character, later growth adding to and altering the structures before the soft parts were withdrawn and partitioned off. In part, too, this appearance is due to silicification, the septa in partially etched specimens being sometimes much shorter where free than where embedded in the portions of limestone remaining in the bottom of the calice. Thus the septa in the calice may have extended in reality nearly if not quite to the pseudocolumella, just as they do below, showing one of the distinctive structural characters of the genus.

The somewhat unusual conformation of the only specimen yet found belonging to this species is probably of little value in determining its specific relations, and may be entirely an individual character. The fact that no secondary septa are shown in the calice and that the primary septa number but 16, instead of 24 to 28, as in L. permiana, distinguish this species from the one last mentioned.

Horizon and locality.—"Dark limestone," Pine Spring, Guadalupe Mountains, Texas (station 2930).

LINDSTRŒMIA sp.

Under this title are included two specimens, each from a different locality, which should not, I feel, be referred to either of the species recognized in this fauna. They are rather small and of a cylindrical shape. Their diameter is 4 mm. and their length 8 mm. The septa number 29 or 30. In one specimen the septa are distinctly separable into primary and secondary, the primary septa extending to the center and uniting with a large axis. In the other specimen the primary and secondary septa can scarcely be distinguished by difference in length.

In its shape this species resembles Lindstrœmia cylindrica, but the number and arrangement of the septa are different, while not only in its smaller size and shape but also in the number of septa does it differ from L. permiana. It is true that young specimens of L. permiana have fewer septa than the large ones, but as a rule fewer also than the form under consideration. Besides, judged by its shape the latter has apparently reached its final or mature condition, while the small corals referred to L. permiana have a different shape and one which from its nature admits of or almost necessitates augmentation in the number of septa, etc., in process of enlargement.

Horizon and locality.—"Dark limestone," Pine Spring (station 2930), and Guadalupe Point (station 3762b), Guadalupe Mountains, Texas.

Genus ZAPHRENTIS Rafinesque.

ZAPHRENTIS? sp.

After removing the coralla referred to Lindstrœmia and Amplexus, a residual group, somewhat varied, yet having a certain amount of unity, remains. These fossils closely resemble L. permiana, but appear to be without the pseudocolumella of that group. The septa are numerous. In an example having a diameter of but 6 mm. 35 were counted. The primary and secondary septa are not readily distinguished and the plates are distorted. They are connected by moderately abundant dissepimental tissue. In a larger example, having a diameter of 10 mm., there appear to be 40 septa, primary and secondary, but they are not very distinct, and I believe that some were overlooked, their irregular growth aiding in making a precise count very difficult. In some of the specimens assigned to this group a pseudocolumella seems to be absent, in others the evidence on this point is lacking, and of no example probably can it be said that the corallum was certainly without a pseudo columella.

Horizon and locality.—"Dark limestone," Guadalupe Point, Guadalupe Mountains, Texas (station 3762b). Delaware Mountain formation, southern Delaware Mountains, Texas (station 2957?). Delaware Mountain formation, Comanche Canyon, Glass Mountains, Texas (station 3763).

Genus AMPLEXUS Sowerby.

AMPLEXUS sp.

The specimens which clearly possess the structure of the group for which the name Lindstrœmia is here used being withdrawn, there remains in our collection a heterogeneous assemblage, consisting of examples which appear more or less clearly to have a different structure and of those whose structure is imperfectly shown. From these coralla has been subtracted a group distinguished by being rather small, slender, and cylindrical and by having, so far as could be observed, the kind of structure characterizing the genus Amplexus. It seems necessary to distinguish two subordinate divisions, one of them represented by specimens from the Glass Mountains and the other by specimens from the Guadalupes. In the former the diameter is 7 to 10 mm. and the subcylindrical corallum is marked by numerous fine longitudinal ridges, likewise by transverse constrictions. There are about 26 primary and the same number of secondary septa. None of the septa reach to the center, and the large axial space thus left was probably crossed by tabulæ. No columella was present. More or less sparse dissepimental tissue occurs around the outer margin. Enough divergence can be noted in the length and character of the septa to indicate the possibility of two species among the fossils of this division, but as my material is scanty, silicified, and difficult to study it did not seem warranted to subject it to the final analysis.

The specimen especially representing the second division has a diameter of 4.5 mm. The growth is irregular, the exterior is marked by a number of angular transverse ridges, but the longitudinal ribs are obscure. There are 15, possibly 16, rather long primary septa. The secondary septa are mere ridges between the primary ones, and dissepimental tissue seems to be absent. This specimen has the appearance of being young or pathologic.

Horizon and locality.—Base of Capitan formation, hill southwest of Guadalupe Point (Station 2906?); "dark limestone," Guadalupe Point (station 3762b), Guadalupe Mountains, Texas. Delaware Mountain formation, Comanche Canyon, Glass Mountains, Texas (station 3763).

Family CYATHOPHYLLIDÆ Milne-Edwards and Haime.

Genus CAMPOPHYLLUM Milne-Edwards and Haime.

CAMPOPHYLLUM TEXANUM Shumard?

Pl. VII, fig. 18.

1859. Campophyllum (?) Texanum. Shumard, Trans. Acad. Sci. St. Louis, vol. 1, p. 388 (date of volume, 1860).

White [Permian] limestone: Guadalupe Mountains.

Shumard gives the foregoing name to a form from the white limestone, his description of which is so inadequate that the name itself is practically invalid. He says of this form:

This is a long, subcylindrical, flexuous species, having a diameter above of about one-third of an inch. It is covered with a thin epithelium. The interior structure is unknown. I place it provisionally in the above genus until I can have an opportunity of examining better specimens.

Locality—White limestone, Guadalupe Mountains.

In our collection there is only one specimen from the same horizon as Campophyllum texanum which can with any probability belong to it, and it is represented by fig. 18 of Pl. VII. It agrees with the original description in all of the characters designated except that the diameter is nearly twice as great, and yet I doubt whether it really represents Shumard's species. It is, however, so far as I can make out—for it is imperfect and somewhat crushed—a true Campophyllum. There are about 50 septa, which did not reach to the center. There is a marginal region intersected by dissepiments, while the central or axial cavity is partitioned by rather distant tabulæ.

As, however, the interior of the real Campophyllum texanum was not known to Shumard, the latter may have belonged to quite another genus and have been a form like Lindstrœmia cylindrica, which, though from a slightly different horizon, had the same diameter and other characteristics much like C. texanum. It may even have been one of the sponges which are not uncommon in the Capitan formation, such as Guadalupia cylindrica, Virgula rigida, etc.

Horizon and locality.—Middle of Capitan formation, Capitan Peak, Guadalupe Mountains, Texas (station 2926).

HEXACORALLA.

Family FAVOSITIDÆ Milne-Edwards and Haime.

Genus CLADOPORA Hall.

CLADOPORA SPINULATA n. sp.

Pl. XVII, figs. 17 and 17a.

This species forms cylindrical, simple, or branching coralla, the diameters of which vary from 4 to 8 mm. The proportion of large and small corrallites varies widely in different coralla. The larger apertures have a nearly uniform diameter of 0.75 mm. The corallum is covered with projecting, spinelike processes, usually lost in weathered specimens, which seem as a rule to originate from the angle where three corrallites come into contact. The mural pores are large, though rather scarce. Septa are represented by internal spinules which appear to be arranged in longitudinal rows. I have not been able to ascertain by observation the exact number of these rows, but estimate that there were nine or ten.

This species and the one following recall especially two middle Paleozoic genera, Cladopora and Striatopora, the latter rather because of the forms which have from time to time been referred to it than from the character and appearance of the genotype. The type species of Cladopora and Striatopora do in fact differ strongly in general aspect, and the Guadalupian species resemble Cladopora seriata rather than Striatopora flexuosa. According to Rominger, however, the two genera are really very similar, and certainly the groups of species at present included under these generic titles have much in common. One of the important structural characters indicated in Hall's original description of Cladopora is the absence of diaphragms. Rominger reports having observed these structures, though usually they are absent. According to the definitions of the author last mentioned, the distinctive characters of the two genera as compared with one another are the thickened and striated apertures in Striatopora and the abundant development of mural pores. In Cladopora the apertures are not thickened, tabulæ are absent or rare, and pseudosepta rudimentary or absent.

In Cladopora spinulata the apertures of the cells are not thickened and striated, and therefore the general appearance is more that of Cladopora than of Striatopora. Diaphragms seem to be absent as a rule from both of the genera mentioned, and none have been observed in C. spinulata. The comparative rarity of mural pores is likewise a point in common with Cladopora, whereas the rows of spines constituting what may be called pseudosepta tend to ally it rather with Striatopora. It is not stated in Rominger's description of Striatopora that these structures extend from the aperture where they are most obvious into the interior of the tube, but it is presumed that this is the case. In Cladopora spinulata they can be seen only below the aperture. This species, therefore, is not entirely in agreement with either of Hall's genera and the recurrence of this type in the Permian is rather suggestive that its characters will be found too far modified for admission into either of the earlier groups. This seems to a certain extent to be the fact in the matter of the septal development of Cladopora spinulata and more especially in the case of Cladopora tubulata. Both from the scantiness and from the silicified condition of my material I am unable to pursue the study of either species so far that an accurate generic diagnosis would be possible, and it seems safer to refer them to Cladopora, to which they are clearly allied and, where they may really by rights belong.

I have referred to this species some specimens from station 2963 which are differently preserved and show somewhat different characters from the others. The others, in brief, are silicified while these, though fragmentary, are calcareous. They are composite coralla, in general respects like the silicified examples. The rather thick walls are pierced by occasional mural pores. Tabulæ appear to be absent, but a striking feature consists of what resemble long septa, which though often much thicker near the walls are very variable in size, in length, and in arrangement. Some of the longer ones extend to the center or beyond, while the others are much shorter. They are not only unequal distances apart, but sometimes as much as half the circumference of a corallite will be unprovided with them. Indeed, in some specimens none at all appear to be present. Owing to the small size of the corallites and the imperfect or partial development of the septalike structures it is difficult to give an exact number for those present. Eight or nine can be counted in several instances and in others there may be four or five fragmentary ones in addition.

So far as I have been able to discover, these septa are not plates but spines, and they are best developed in the interior parts of the corallum and least developed in the peripheral parts. It is of course the latter which are seen in silicified specimens, where septal spines can sometimes be detected, though they do not form a striking feature, and thus I believe it highly probable that these calcareous examples, which at first look very different because of their apparently well-developed septa, are really the same species as the silicified ones.

Horizon and locality.—Base of Capitan formation, hill southwest of Guadalupe Point (station 2906); "dark limestone," Pine Spring (station 2930), near Guadalupe Point (stations 3762b and 3762e), and hill southwest of Guadalupe Point (station 2924); Delaware Mountain formation, Guadalupe Point (station 2963), Guadalupe Mountains, Texas. Delaware Mountain formation, southern Delaware Mountains, Texas (stations 2962 and 2969). Delaware Mountain formation, Comanche Canyon, Glass Mountains, Texas (station 3763).

CLADOPORA? TUBULATA n. sp.

Pl. XXV, figs. 5 and 5a.

In this species the corallites form small, more or less branching coralla, which seem to broaden out at the base or on occasion and become somewhat incrusting. The corallites are nearly of equal size and have a diameter of about three-fourths of a millimeter. They are not very thickly clustered and their apertures are sometimes separated by considerable intervals. They are strongly inclined to the axis, so that the aperture is semicircular or crescentiform, with a projecting lower lip, yet individual corallites contrive to elevate themselves above the general surface as short, separate tubular cells. The walls are thick, and I have ascertained that in a few instances they are pierced by mural pores, but these structures seem to be only occasional. No septa or tabulæ have been observed.

The general resemblance of this fossil to Cladopora spinulata, which occurs at nearly if not quite the same horizon seems to warrant a reference of both to the same genus, but while the latter appears to have nearly all the characters of a true Cladopora, the present species must certainly be regarded as a peculiar and aberrant form.

Horizon and locality.—Delaware Mountain formation, Diablo Mountains, Texas, as reported (station 3764). Delaware Mountain formation, southern Delaware Mountains, Texas (station 2969).

Family AULOPORIDÆ Nicholson.

Genus AULOPORA Goldfuss.

AULOPORA sp.

Growing upon an indeterminable species of Fenestella there was found at station 2969 an Aulopora which presents no appreciable differences from much older types of the genus. Portions of three corallites in a linear series are present, and the whole has a length of only 6-1/2 mm., so that the species is a very small one. The length of each corrallite was probably about 2-1/2 to 3 mm. and the greatest diameter 1 mm. or a little less. Each corallite appears to have been a regularly enlarging cone slightly curved, if at all, developing a single offshoot by gemmation when it had attained two-thirds or three-fourths the full size.

These data, however, can not be made exact, owing to imperfections in the material.

Horizon and locality.—Delaware Mountain formation, southern Delaware Mountains, Texas (station 2969).