m k'RtyFoV' II! \| SIR" UY Of CALIFORNIA UNIVERSITY OF CALIFORNIA. FROM THE LIBRARY OF DR. JOSEPH LECONTE. GIFT OF MRS. LECONTE. EARTH SCIENCES JJBBABX No. AIR-BREATHERS OF THE COAL PERIOD A DESCRIPTIVE ACCOUNT OF TH REMAINS OF LAND ANIMALS FOUND IN THE COAL FORMATION OF NO A' A SCOTIA WITH REMARKS ON THEIR BEARING ON THEORIES OF THE FORMATION OP COAL AND OF THE ORIGIN OF SPECIEP, BY J. W. DAWSON, LL.D., F.R.S., F.G.S., ETC., principal of |Rc6ill KmbmHi?, WITH ILLUSTKATIONS DAWSON 3 BROTHERS, GREAT ST. JAMES STREET, LONDON, H. BAILLIERE ; NEW YORK, BAILLIERE, BROTHERS. 1863. OF THE UNIVERSITY OF AIR-BREATHERS OF THE COAL PERIOD, IF AIR-BREATHERS OP THE COAL PERIOD: A DESCRIPTIVE ACCOUNT OF THE REMAINS OP LAND ANIMALS FOUND IN THE COAL FORMATION OP NOVA SCOTIA, WITH REMARKS ON THEIR BEARING ON THEORIES OP THE FORMATION OF COAL AND OF THE ORIGIN OF SPECIES. BY J. W. DAWSON, LL.D., F.R.S., F.G.S., ETC., inHpal flf gftc&ill Winiijtriiiy. WITH ILLUSTRATIONS. t)AWSON BROTHERS, GREAT ST. JAMES STREEf . LONDON, H. BAILLIERE J NEW YORK, BAILLIERE BROTHERS. 1863. -J33 EARTH SCIENCES LIBRARY CONTENTS. PAGES. 1 INTRODUCTORY, 1 2 FOOTPRINTS, 5 3 BAPHETES PLANICBPS, 10 4 DBNDRERPETON ACADIANUM, 17 5 DENDRERPETON OWBNI, 32 6 REMAINS OF SKIN AND SCALES, 34 7 HYLONOMUS LTELLI, 40 8 HYLONOMUS ACIBDBNDATDS, 49 9 HYLONOMUS WYMANI, 52 10 HYLBRPETON DAWSONI, 55 11 OTHER REPTILIAN REMAINS, 58 12 INVERTEBRATE AIR-BREATHERS, 62 13 CHARACTERS OF THE ANIMALS DESCRIBED, 65 14 CONCLUDING REMARKS, 68 PKEFACE. A certain moral obligation rests on the discoverer or pos- sessor of new and valuable fossils, to make them known as extensively as possible to the scientific world. This he may do either personally or by the aid of others more conversant with the class of objects in question. I have generally pre- ferred the latter course for all objects not included in my own special lines of investigation ; and in the case of the subjects of the present brochure ^have presented them, as dis- covered, to the investigation of naturalists specially engaged in the study of such remains. Through their kindness my specimens have been extensively illustrated, chiefly in the pages of the Journal of the Geological Society of London. I have, however, found it impossible to bring out in this way all the details desirable, and to present a connected view of the facts. Hence the present publication, in which I give a summary of all that I have been able to ascertain of the land animals of the coal period in Nova Scotia, and endeavour to make my collection of their fossil remains the common pro- perty of all geologists and naturalists, thereby discharging the obligations under which I am laid by having had these precious relics placed by Providence in my hands. IV PREFACE. To do this has cost me some sacrifice. The time required has been snatched from scanty intervals of rest in the midst of daily severe toil, and above all it has necessarily been taken from the prosecution of those researches in the fossil bo- tany of the palaeozoic period, to which I have devoted special attention for many years, and which are yet very incomplete. These circumstances, and the scanty means of reference and comparison at my disposal, I must plead as excuses for any imperfections which may appear in the work. The lithographed illustrations must not be taken as evi- dence of the state of art in Canada. They are merely trans- fers from my own rough tracings of the objects, and the only merit which they claim is that of accuracy of outline. The photograph inserted in some of the copies, I owe to the kindness of Mr. G. R. Prowse, an amateur artist of this city. It presents an accurate magnified picture of some of the principal remains ; and deserves much praise as a highly successful application of microscopic photography to very difficult objects. It is proper to add that the greater part of the matter of this memoir has appeared in the Canadian Naturalist and Geologist for 1863. J. W. DAWSON. McGiLL UNIVERSITY, MONTREAL, Jnne, 1863. THE AIR-BREATHERS OF THE COAL PERIOD IN NOVA SCOTIA. L INTRODUCTORY. The animal population of the earth during the older or palaeo- zoic period of its geological history, is known to us chiefly through the medium of remains preserved in rocks deposited in the bed of the ocean. In such rocks we have little reason to expect an abundant representation of the animals of the land, even if these existed at the time plentifully on the neighbouring shores. Per- haps for this reason, perhaps because there were then no land animals, the organic remains of the Cambrian, Silurian, and Lower Devonian rocks consist, in so far as animal life is concerned, solely of marine species. In the Upper Silurian and Lower De- vonian, however, land plants begin to appear ; and in the Upper Devonian these are so numerous and varied as to afford a proba- bility that animals also tenanted the land. Indeed, Mr. Hartt, of St. John, has just announced the discovery of remains, which he be- lieves to be attributable to insects, in the rich pi ant-bearing Upper Devonian beds of that locality.* It is true also that reptiles of * In a letter to the author. It is to be hoped that descriptions of these interesting remains may soon be published. 2 AIR-BREATHERS OF THE COAL PERIOD. ,-v high organization have been found in beds referred to the UppwP Devonian, at Elgin, in Scotland ; bat so much doubt rests on the age of these beds, that it is unsafe at present to regard them as affording evidence of reptilian life at so early a period. /// That there was dry land, even in the Lower Silurian period, we know, and can even trace its former shores. In Canada our old Laurentian coast extends for more than a thousand miles, from Labrador to Lake Superior, marking the southern border of the nucleus of the American continent in the Lower Silurian period. Along a great part of this ancient coast we have the sand-flats of the Potsdam Sandstone, affording very favorable conditions for the imbedding of land animals, did these exist ; still, notwithstand- ing the zealous explorations of the Geological Survey, and of many amateurs, no trace of an air-breather has been found. I have myself followed the Lower Silurian beds up to their ancient limits in some localities, and collected the shells which the waves had dashed on the beach, and have seen under the Silurian beds, the Laurentian rocks pitted and indented with weather marks, showing that this old shore was then gradually subsiding ; yet the record of the rocks was totally silent as to the animals that may have trod the shore, or the trees that may have waved over it. All that can be said is that the sun shone, the rain fell, and the wind blew as it does now, and that the sea abounded in living creatures. The eyes of trilobites, the weathered Lauren- tiau rocks, the wind-ripples in the Potsdam sandstone, the rich fossils of the limestones, testify to these things. The existence of such conditions would lead us to hope that land animals may yet be found in these older formations. On the other hand, the gradual failure of one form of life after another, as we descend in the geological series, and the absence of fishes and land plants in the older Silurian rocks, might induce us to believe that we have here reached the beginning of animal life, and have left far behind us those forms that inhabit the land. Even in the Carboniferous period, though land plants abound, air-breathers are few, and most of them have only been recently AIR-BREATHERS OP THE COAL PERIOD. 3 recognized. We know, however, with certainty that the dark and luxuriant forests of the coal period were not destitute of ani- mal life. Reptiles crept under their shade, land-snails and milli- pedes fed on the rank leaves and decaying vegetable matter, and insects flitted through the air of the sunnier spots. Great interest attaches to these creatures; perhaps the first-born species in some of their respective types, and certainly belonging to one of the oldest land faunas, and presenting prototypes of future forms equally interesting to the geologist and the zoologist. It has happened to the writer of these pages to have had some share in the discovery of several of these ancient animals. The coal formation of Nova Scotia, so full in its development, so rich in fossil remains, and so well exposed in coast cliffs, has afforded ad- mirable opportunities for such discoveries, which have been so far improved that at least eight out of the not very large number of known Carboniferous land animals, have been obtained from it.* The descriptions of these creatures, found at various times and at various places, are scattered through papers ranging in date from 1844 to!862,f and are too fragmentary to give complete informa- tion respecting the structures of the animals, and their conditions of existence. I have, for some time, designed to prepare a resume* of the published facts, with the addition of such new points as may arise from the further study of the specimens, but have been deterred by the incomplete state of my knowledge, and the prospect of further discoveries. So much has, however, now been done, and so many difficulties have been removed by the labours of several eminent naturalists who have examined the specimens, that I think the time has arrived when such a work may be under- taken with advantage to science. * It appears that five species of Carboniferous reptiles have been re- cognised on the continent of Europe, three in Great Britain, and four in the United States. More full references will be made to these in the sequel. t Papers by Lyell, Owen, and the author, in the Journal of the Geolo- gical Society of London, vols. i, ii, ix, x, xi, xvi, xvii, xviii. 4 AIR-BREATHERS OF THE COAL PERIOD. In now endeavouring more fully to introduce the tenants of the coal forests of Nova Scotia to the notice of geologists and of the general reader, I shall take them nearly in the order in which they have become known to me, and shall not scruple to indulge in some gossip as to the circumstances of their discovery, and in some speculations as to their modes of life. I shall however endeav- or carefully to sum up the facts ascertained as to their structure, and their relation to other creatures, whether their contemporaries or successors. AIR-BREATHERS OF THE COAL PERIOD. II. FOOTPRINTS. Plate I. It has often happened to geologists, as to other explorers of new regions, that footprints on the sand have guided them to the inhabitants of unknown lands. The first trace ever observed of reptiles in the carboniferous system, consisted of a series of small but well-marked footprints found by Sir W. E. Logan, in 1841, in the lower coal measures of Horton Bluff, in Nova Scotia ; and as the authors of all our general works on geology have hitherto, in so far as I am aware, failed to do justice to this discovery, I shall notice it here in detail. In the year above mentioned, Sir William, then Mr. Logan, examined the coal fields of Pennsylvania and Nova Scotia, with the view of studying their structure, and ex- tending the application of the discoveries as to Stigmaria under- clays which he had made in the Welsh coal fields. On his return to England, he read a paper on these subjects before the Geologi- cal Society of London, in which he noticed the discovery of rep- tilian footprints at Horton Bluff. The specimen was exhibited at the meeting of the Society, and was, I believe, admitted on the high authority of Prof. Owen, to be probably reptilian. Unfortun- ately, Sir William's paper appeared only in abstract in the Trans- actions ; and in this abstract, though the footprints are mentioned, no opinion is expressed as to their nature. Sir William's own opinion is thus stated in a letter to me, dated June, 1843, when he was on his way to Canada, to commence the survey which has since developed so astonishing a mass of geological facts. " Among the specimens which I carried from Horton Bluff, one is of very high interest. It exhibits the footprints of some reptilian animal. Owen has no doubt of the marks being genuine footprints. The rocks of Horton Bluff are below the gypsum of that neigh- bourhood ; so that the specimen in question (if Lyell's views are 6 AIR-BREATHERS OF THE COAL PERIOD. correct*) comes from the very bottom of the coal series, or at any rate very low down in it, and demonstrates the existence of reptile s at an earlier epoch than has hitherto been determined ; none having been previously found below the magnesian limestone, or to give it Murchison's new name, the * Permian era.' " This extract is of interest, not merely as an item of evidence in relation to the matter now in hand, but as a mark in the progress of geological investigation. For the reasons above stated, the im- portant discovery thus made in 1841, and published in 1842, was overlooked ; and the discovery of reptilian bones by Von Dechen, at Saarbruck, in 1844, and that of footprints by Dr. King in the same year, in Pennsylvania, have been uniformly referred to as the first observations of this kind. This error I now desire to correct, not merely in the interest of truth, but also in that of my friend Sir William Logan, and of my native province of Nova Scotia ; and I trust that henceforth the received statement will be, that the first indications of the existence of reptiles in the coal period, were ob- tained by Logan, in the lower coal formation of Nova Scotia, in 1841. Insects and arachnidans, it may be observed, had pre- viously been discovered in the coal formation in Europe. The original specimen of these footprints is still in the collec- tion of Sir William Logan. It is a slab of dark colored sand- stone, glazed with fine clay on the surface ; and having a series of seven footprints in two rows, distant about 3 inches ; the distance of the impressions in each row being 3 or 4 inches, and the individual impressions about 1 inch in length. They seem to have been made by the points of the toes, which must have been armed with strong and apparently blunt claws, and appear as if either the surface had been somewhat firm, or as if the body of the animal had been partly water-borne. In one place only is there a distinct mark of the whole foot, as if the animal had exerted an unusual pressure * Sir Charles Lyell bad then just read a paper announcing his discovery that the gypsiferous system of Nova Scotia is Lower Carboniferous, in which he mentions the footprints referred to, as being reptilian. AIR-BHEATHERS OF THE COAL PERIOD. 7 in turning or stopping suddenly. One pair of feet, the fore feet I presume, appear to have had four claws ; the other pair may have had three or four, and it is to be observed that the outer toe, as in the larger footprints discovered by Dr. King, projects in the man- ner of a thumb, as in the cheirotherian tracks of the Trias. No mark of the tail or belly appears. The impressions are such as may have been made by some of the reptiles to be described in the sequel, as, for instance, by Dendrerpeton Acadianum. Attention having been directed to such marks by these obser- vations of Sir William Logan, several other discoveries of the same kind were subsequently made, in various parts of the pro- vince, and in different members of the carboniferous system. The first of these, in order of time, was made in 1844, in beds of red sandstone and shale near Tatamagouche, in the eastern part of Nova Scotia, and belonging to the upper or newer mem- bers of the coal measures. In examining these beds with the view of determining their precise geological age, I found on the surface of some of them impressions of worm-burrows, rain drops, and sun- cracks, and with these, two kinds of footprints, probably of rep- tilian animals. One kind consisted of marks, or rather scratches, as of three toes, and resembling somewhat the scratches made by the claws of a tortoise in creeping up a bank of stiff clay ; they were probably of the same nature and origin with those found by Logan at Horton. The others were of very different appearance. They consisted of two series of strongly marked elongated impres- sions, without distinct marks of toes, in series four inches distant from each other, and with an intervening tail mark. They seem to have been produced by an animal wading in soft mud, so thai deep holes, rather than regular impressions, marked its footsteps, and that in the hind foot, the heel touched the surface, giving a plantigrade appearance to the tracks. Rain marks had been impressed on the surface after the animal had passed over it, and these had probably aided in obliterating the finer parts of the im- pressions. These observations were published in the Journal of the Geological Society of London, vols. 1st and 2nd. 8 AIR-BREATHERS OP THE COAL PERIOD. Shortly afterward, Dr. Harding, of Windsor, when examining a cargo of sandstone which had been landed at that place from Parrsboro', found on one of the slabs a very distinct series of foot- prints each with four toes, and a trace of the fifth. Dr. Hard- ing's specimen is now in the museum of King's College, Windsor. Its impressions are more distinct, but not very different otherwise from those above described as found at Horton Bluff. The rocks at that place are probably of nearly the same age with those of Parrsboro'. I afterward examined the place from which this slab had been quarried, and satisfied myself that the beds are Carboni- ferous, and probably Lower Carboniferous. They were ripple- inarked and sun-cracked, and I thought I could detect trifid foot- prints, though more obscure than those in Dr. Harding's slab. Similar footprints are also stated to have been found by Dr. Gesner, at Parrsboro'. T have since observed several instances of such impressions at the Joggins, at Horton, and near Windsor, showing that they are by no means rare, and that reptilian animals existed in no incon- siderable numbers throughout the coal-field of Nova Scotia, and from the beginning to the end of the carboniferous period. Two of the more interesting examples are figured with those already des- cribed. On comparing these with one another, it will be observed that Logan's, Harding's, and one of mine are of similar general character, and may have been made by one kind of animal, which must have had the fore and hind feet nearly of equal size. The other belongs to a smaller animal, which probably travelled on longer limbs, more in the manner of an ordinary quadruped. Its toes cannot be distinguished. On the whole, these footprints, while differing from those found by Dr. King in Pennsylvania, do not prove the existence of any kind of animal distinct from those to be described in the sequel, and known to us by the pre- servation of portions of their skeletons. The study of these footprints shows that the animals which produced them may, in certain circumstances, have left impres- sions of only 'two or three of their toes, while in other cir- AIR-BREATHERS OF THE COAL PERIOD. cumstances all may have left marks ; and that, when wading in deep mud, their footprints were altogether different from those made on hard sand or clay. In some instances the impressions may have been made by animals wading or swimming in water, while in others the rain-marks and sun-cracks afford evidence that the surface was a sub-aerial one. They are chiefly inter- esting as indicating the wide diffusion and abundance of the creatures producing them, and that they haunted tidal flats and muddy shores, perhaps emerging from the water that they might bask in the sun, or possibly searching for food among the rejecta- menta of the sea, or of lagunes and estuaries. EXPLANATION OF PLATE I. Footprints of Reptiles, fyc. Fig. 1. Footprints discovered by Sir W. E. Logan, in the Lower Car- boniferous beds of Horton Bluff, in 1841 ; reduced to one- fourth of the natural size, (la) one of the impressions, natu- ral size. " 2. Footprints discovered by Dr. Harding, in the Lower Carbonife- rous beds of Parrsboro'; one-fourth bf the natural size. (2a) Prints of fore and hind foot natural size. This figure is from a rubbing kindly taken for me by Prof. How, of Wind- sor. " 3. Footprints from the Coal Measures of the South Joggins ; one-fourth natural size. (3 a) One of the impressions natu- ral size. " 4.- Smaller footprints from the South Joggins ; one-fourth natu- ral size. " 5. Skin of a reptile, found with remains of a small Dendrerpeton, in an erect tree at the Joggins. (a) Scaly portions ; (b) Traces of hind leg? and small scales, (c) (d) Portions magnified, showing scales. 10 AIR-BREATHERS OF THE COAL PERIOD. III. BAPHETES PLANICEPS. Plate II. In the summer of 1851, 1 had occasion to spend a day at the Albion mines; and on arriving at the railway station in the after- noon, found myself somewhat too early for the train. By way of improving the time thus left on my hands, I betook myself to the examination of a large pile of rubbish, consisting of shale and iron- stone from one of the pits, and in which I had previously found scales and teeth of fishes. In the blocks of hard carbonaceous shale and earthy coal, of which the pile chiefly consisted, scales, teeth and coprolites often appeared on the weathered ends and surfaces as whitish spots. In looking for these, I observed one of much greater size than usual, on the edge of a block, and on splitting it open, found a large flattened skull, the cranial bones of which remained entire on one side of the mass, while the palate and teeth, in a more or less fragmentary state, came away with the other half. Carefully trimming the larger specimen, and gathering all the smaller fragments, 1 packed them up as safely as possible, and returned from my little excursion much richer than I had hoped. The specimen, on further examination, proved somewhat puz- zling. I supposed it to be, most probably, the head of a large ganoid fish ; but it seemed different from any thing of this kind with which I could compare it ; and at a distance from compara- tive anatomists, and without sufficient means of determination, I dared not refer it to anything higher in the animal scale. Hop- ing for further light, I packed it up with some other specimens^ and sent it to the Secretary of the Geological Society of London, with an explanatory note as to its geological position, and request- ing that it might be submitted to some competent osteologist for examination. For a year or two however, it remained as quietly AIR-BREATHERS OP THE COAL PERIOD. 11 in the Society's collection as if in its original bed in the coal mine, until attention having been attracted to such remains by the dis- coveries made by Sir Charles Lyell and myself in 1852, at the South Joggins, and published in 1853,* the Secretary or President of the. Society re-discovered the specimen, and handed it to Prof. Owen, by whom it was described in Dec., 1853,f under the name of Baphctes planiccps, which may be interpreted the " flat-headed- diving animal*' in allusion to the flatness of the creature's skull, and the possibility that it may have been in the habit of diving. The parts preserved in my specimen are the bones of the an- terior and upper part of the skull in one fragment, and the teeth and palatal bones in others. With respect to the former, Prof. Owen recognizes in it the premaxillary (p.) (Fig. 1) and maxillary bones, (m.) both presenting traces of the sockets of teeth, which appear to be in a single series ; but other fragments show that in part at least, they were in double series. The central portion of the skull and part of the orbits are made up of the nasals, (n.) the frontal (fr.) and the prefrontal (pf.) in a manner characteristic of the Labyrinthodont reptiles, and not of fishes. The upper sur- face of the bone, seen in some detached fragments, as in Fig. 4, has a pitted surface, like that of the stone of a peach, as is the case also in the Labyrinthodonts. In sections under the microscope, the bone shows vascular canals and small rounded bone-cells, a structure observed in Labyrinthodon, and in some of the larger Saurians (Figs. 2 and 8). The teeth are conical, and somewhat curved, the outer series from a line to two lines in diameter, and the inner series three lines or more (Figs. 3 and 5). They are implanted in shallow sockets in the maxillary and premaxillary bones, and are anchylosed to the sockets. For the lower third, the outer surface presents shallow vertical grooves, conformably with the plicated character of the internal structure (Figs. 3, 7, and 10). The upper portion is smooth, and its internal structure presents * Journal of Geological Society of London, vol. ix. f Journal of Geological Society, vol. x ; and additional notes, vol. xi. 12 AIR-BtlEATHERS OP THE COAL PEKIOB. merely radiating tubes of ivory, and concentric layers, (Figs. S 7 6, and 9). The whole of these characters are regarded as allying the animal with the great crocodilian frogs of the Trias of Europe, first known as Cheirotkerians, owing to the remarkable hand-like impressions of their feet, and afterwards as Labyrinthodonts, from the beautifully complicated convolutions of the ivory of their teeth. The only additional remains attributable to this creature, found since the publication of Professor Owen's description, are the bone represented in Fig. 12, and the scute or scale represented in I?ig. 11. The former may be a scapular or sternal bone, and, if so, would warrant the belief that the creature possessed anterior limbs of considerable size ; the proportion relatively to the skull being much the same as in the American bullfrog. The latter is marked in the same way as the bones of the head, and would indicate that JSaphetes was protected by bony dermal scales, re- sembling those of the crocodile. There is one point illustrated by the bone represented in Fig. 12, to which I would earnestly invite the attention of comparative anatomists. It is the distortion to which bones are subjected when imbedded in soft deposits, especially those containing vegetable matter. In modern peat bogs, skulls have been found nearly as pliable as leather, owing to the partial removal of their phosphate of lime ; and in clay beds they are often found softer than chalk, from the removal of their animal matter. Human skulls, buried under no great weight of earth, have often been strangely distorted from this posthumous softening. Even teeth . are affected in this way. In the remains of the old Indian village of Hochelaga, #t Montreal, while the teeth of bears are found in the drier and more sandy soil quite perfect and unal- tered ; in damp places, and where they a.re imbedded in organic matter thrown out from the cabins, they are softened, so that a large canine may be easily compressed between the finger and thumb. Changes of this kind have no doubt been experienced by all the bones imbedded in coal, carbonaceous shale, and similar deposits ; and in the great compression which the mass has ex- AIR-BREATHERS OP THE COAL PERIOD. 13 perienced, the bones, yielding with it, have been flattened and dis- torted in the most remarkable manner. In the bones, in short, as in the plants of the coal, the flattened specimen must not be ac- cepted as representing the original form. - The bone represented in Fig. 12, for example, must have been strong, and nearly cylin- drical in its middle portion, and much curved ; but it has given way to pressure, and has as it were been faulted along certain lines, so as to lose almost entirely its original relief. The sec- tional view in Fig. 13, represents some of these faults, with the present profile of the bone, its original outline being represented by the dotted line. The title of the present species to the speci- fic name planiceps, is also in part dependent on this cause. No doubt its head, like that of other batrachians, was somewhat flat, but this has been much increased by pressure ; in so much that the fragments of the specimen show that the palate is almost brought into contact with the roof of the skull, and that scarcely a quarter of an inch is left in some places for the depth of the great orbits. The interior of the skull must have been filled with soft slime, and this has been compressed into a hard stone. In like manner, I shall have occasion to show, in reference to other rep- tiles of the coal, that their bones have been much altered in form, so that limb bones, which, when buried in a nearly erect position, show broad and flat articulating surfaces, have these compressed into mere edges, when the specimens lie horizontally, and that hol- low bones have been fractured longitudinally, and pressed almost perfectly flat. Anatomisls may be very easily misled by such ap- pearances, and should carefully enquire as to tbe possibility of their occurrence, before deducing inferences from the forms of bones. Of tbe general form and dimensions of Baphetes, the facts at present known, do not enable us to say much. Its formidable teeth and strong maxillary bones show that it must have devoured animals of considerable size, probab ! y the fishes whose remains are found with it, or the smaller reptiles of tbe coal. It must in short have been crocodilian, rather than frog-like, in its mode of 14 AIR-BREATHERS OF THE COAL PERIOD. life ; but whether, like the labyrinthodonts, it had strong limbs and a short body, or like the crocodiles, an elongated form and a power- ful natatory tail, the remains do not decide. One of the limbs, or, a vertebra of the tail would settle this question, but neither have as yet been found. That there were large animals of the laby- rinthodontal form in the coal period, is proved by the footprints discovered by Dr. King in Pennsylvania, which may have been produced by an animal of the type of Baphetes. On the other hand that there were large swimming reptiles, seems established by the recent discovery of the vertebrae of Eosaurus Acadianus, at the Joggins, by Mr. Marsh.* The locomotion of fiaphetes must have been vigorous and rapid, but it may have been 'effected both on land and in water, and either by feet or tail, or both. With the nature of its habitat we are better acquainted. The area of the Albion Mines coal field was somewhat exceptional in its character. It seems to have been a bay or indentation in the Silurian land, separated from the remainder of the coal-field by a high shfngle beach, now a bed of conglomerate. Owing to this circumstance, while in the other portions of the Nova Scotia coal- field, the beds of coal are thin, and alternate with sandstones and shales, at the Albion Mines a vast thickness of almost unmixed vegetable matter has been deposited, constituting the 'main seam' of thirty-eight feet thick,and the 'deep seam' twenty -four feet thick, as well as still thicker beds of highly carbonaceous shale. But, though the area of the Albion coal measures was thus separated, and preserved from marine incursions, it must have been often sub- merged, and probably had connection with the sea, through rivers or channels cutting the enclosing beach. Hence beds of earthy matter occur in it, containing remains of large fishes. One of the most important of these is that known as the " Holing stone," a band of black highly carbonaceous shale, coaly matter, and clay ironstone, occurring in the main seam, about five feet below its roof, and varying in thickness from two inches to nearly two feet. * Silliman's Journal, 1859. AIR-BREATHERS OF THE COAL PERIOD. 15 It was from this band, that the rubbish-heap, in which I found the skull of Baphetes planiceps, was derived. It is a laminated bed, sometimes hard and containing much ironstone, in other places soft and shaly : but always black and carbonaceous, and often with layers of coarse coal, though with few fossil plants retaining their forms. It contains large round flat scales and flattened curved teeth, which I attribute to a fish of the genus Rhizodus, resem- bling, if not identical with, R. lancifer, Newberry. With these are double pointed shark-like teeth, and long cylindrical spines of a species of Diplodus, which I have named t). acinaces.\ There are also shells of the minute Spirorbis, so common in the coal measures of other parts of Nova Scotia, and abundance of frag- ments of cpprolitic matter. I have also observed in it a few scales having the peculiar one-sided form of those of Archegosaurus and Dendrerpeton ; and which I may possibly describe and figure, among miscellaneous indications of unknown creatures, in the end of this memoir. It is evident that the " Holing stone " indicates one of those periods in which the Albion coal area, or a large part of it, was under water, probably fresh or brackish, as there are no properly marine shells in this, or any of the other beds of this coal series. We may then imagine a large lake or lagune, loaded with trunks of trees and decaying vegetable matter, having in its shallow parts, and along its sides, dense brakes of Calamites, and forests of Sigil- laria, Lepidodendron, and other trees of the period, extending far on every side as damp pestilential swamps. In such a habitat, uninviting to us, but no doubt suited to Baphetes, that creature crawled through swamps and thickets, wallowed in flats of black mud, or swam and dived in search of its finny prey. It was, in so far as we know, the monarch of these swamps, though there is evidence of the existence of similar creatures of this type quite as large in other parts of the Nova Scotia coal field ; but my notice of these I defer for the present, in hope that additional facts may f Supplement to Acadian Geology, pp. 43 and 50. 16 AIR-BREATHERS OP THE COAL PERIOD. be discovered in respect to them. If this should not be the case, they will be noticed among miscellaneous remains in the sequel. EXPLANATION OF PLATE II. Baphetes planiceps. Fig. 1. Skull seen from below, half natural size. " 2. Portion of bone of skull magnified, to show vascular canals and bone-cells. " 3. One of the largest teeth, natural size. 4. Sculpturing of skull, and margin of orbit, natural size. 5. Fragment of maxillary bone, with four teeth of the outer series* and one of the inner large teeth, the points of the teeth re- stored from fragments in other specimens. " 6 and 7. Sections of a tooth magnified : 6, upper part ; f , lower part, with convoluted dentine. " 8. Section of bone in Fig. 2, more highly magnified. " 9 and 10. Sections of tooth represented in Figs. 6 and 7, natural size. u 11. Dermal scale found with remains of Baphetes. " 12. Scapular or sternal bone found with remains of Baphetes. 13. Longitudinal section of the middle of the same, showing the manner in which it has been crushed. AIR-BREATHEKS OF THE COAL PERIOD. 17 IV. DENDRERPETON AOADIANUM. Plate III. The geology of Nova Scotia is largely indebted to Sir Charles Lyell. Though much had previously been done by others, his personal explorations in 1842, and his paper on the gypsife- rous formation, published in the following year, first gave form and shape to some of the more difficult features of the geo- logy of the country, and brought it into relation with that of other parts of the world. In geological investigation, as in many other things, patient plodding may accumulate large stores of fact, but the magic wand of genius is required to bring out the true value and significance of these stores of knowledge. It is scarcely too much to say that the explorations of a few weeks, and subsequent study of the subject by Sir Charles, with the impulse and guidance given to the labors of others, did as much for Nova Scotia, as might have been effected by years of laborious work under less competent heads. Sir Charles naturally continued to take an interest in the geolo- gy of Nova Scotia, and to entertain a desire to explore more fully some of those magnificent coast sections which he had but hastily examined ; and when, in 1851, he had occasion to revisit the United States, he made an appointment with the writer of these pages to spend a few days in renewed explorations of the cliffs of the South Joggins. The object specially in view was the thorough examina- tion of the beds of the true coal measures, with reference to their contained fossils, and the conditions of accumulation of the coal ; and the results were given to the world in a joint paper on " The re- mains of a reptile and a land-shell discovered in the interior of an erect tree in the coal measures of Nova Scotia," and in the writer's paper on the " Coal Measures of the South Joggins ;"* while other important investigations grew out of the following up of these * Journal of the Geological Society of London ; Vols. ix and x j and Acadian Geology. 18 AIR-BREATHERS OP THE COAL PERIOD. researches, and much matter in relation to the vegetable fossils still remains to be worked up. It is with the more striking fact of the discovery of the remains of a reptile in the coal measures that we have now to do. The South Joggins Section is, among other things, remarkable for the number of beds which contain remains o erect trees imbedded in situ: these trees are for the most part Sigillariae, varying in diameter from six inches to five feet. They have grown in underclays and wet soils, similar to those in which the coal was accumulated; and these having been submerged or buried by mud carried down by inundations, the trees, killed by the accu- mulations around their stems, have decayed, and their tops being broken off at the level of the mud or sand, the cylindrical cavi- ties, left open by the disappearance of the wood, and preserved in their form by the greater durability of the bark, have been filled with sand and clay. This, now hardened into stone, constitutes pillar-like casts of the trees, which may often be seen exposed in the cliffs, and which, as these waste away, fall upon the beach. The sandstones enveloping these pillared trunks of the ancient Sigillarise of the coal, are laminated or bedded, and the laminae, when exposed, split apart with the weather, so that the trees themselves become split across; this being often aided by the arrangement of the matter within the trunks, in layers more or less corresponding to those without. Thus one of these fossil trees usually falls to the beach in a series of discs, somewhat resembling the grindstones which are extensively manufactured on the coast. The surfaces of these fragments often exhibit remains of plants which have been washed into the hollow trunks and have been imbedded there ; and in our explorations of the shore, we always carefully scrutinized such specimens, both with the view of observ- ing whether they retained the superficial markings of Sigillariae, and with reference to the fossils contained in them. It was while examining a pile of these " fossil grindstones," that we were sur- prised by finding on one of them what seemed to be fragments of bone. On careful search other bones appeared, and they had the AIR-BREATHERS OF THE COAL PERIOD. 19 aspect, not of remains of fishes, of which many species are found fossil in these coal measures, but rather of limb-bones of a quadru- ped. The fallen pieces of the tree were carefully taken up, and other bones disengaged, and at length a jaw with teeth made its appearance. We felt quite confident, from the first, that these bones were reptilian ; and the whole, being carefully packed and labelled, were taken by Sir Charles to the United States, and sub- mitted to Prof. J. Wyman of Cambridge ; who recognized their rep- tilian character, and prepared descriptive notes of the principal bones, which appeared to have belonged to two species. He also obseryed among the fragments an object of different character, apparently a shell ; which was recognized by Dr. Gould of Boston, and subsequently by Mr. Deshayes, as probably a land-snail, and has since been named Pupa vetusta. The specimens were subsequently taken to London and re-exa- mined by Prof. Owen, who confirmed Wyman's inferences, added other characters to the description, and named the larger and better preserved species Dendrerpeton Acadianum, in allusion to its discovery in the interior of a tree, and to its native country of Acadia or Nova Scotia. With the aid of Plate III, I shall now endeavour to describe this species as fully as the materials at my command will allow, and shall then make some remarks on its affinities, habitat, and mode of life. It is necessary to state in explanation of the fragmentary character of the remains repre- sented in the plate, that in the decay of the animals imbedded in the erect trees at the Joggins, their skeletons have become disar- ticulated, and the portions scattered, either by falling into the in- terstices of the vegetable fragments in the bottom of the hollow trunks, or by the water with which these may have sometimes been partly filled. We thus can obtain only separate bones ; and though all of these are no doubt present in each case, it is impossible in break- ing up the hard matrix to recover more than a small proportion of them. For this reason I have been obliged tohave recourse, not merely to the original specimen whose discovery is noticed above, but to three others subsequently obtained by me ; all however belong- 20 AIR-BREATHERS OF THE COAL PERIOD. ing, on the evidence of the 'teeth and more important bones, to one species, and all being nearly, though not absolutely, of the same size. It is also proper to state that in the case of the original specimen, and another still more perfect one, both of which are now in London, I have been able to refer only to the published plates, and *o add to these from parts of two additional individuals still in my own collection. In form, Dendrerpeton Acadianum was probably lizard- like ; with a broad flat head, short stout limbs and an elongated tail ; and having its skin, and more particularly that of the belly, pro- tected by small bony plates closely overlapping each other. It may have attained the length of two feet. The form of the head is not unlike that of Baphetes, but longer in proportion ; and much resembles that of the labyrinthodont reptiles of the Trias (Fig. 1). The bones of the skull are sculptured as in Baphetes, but in a smaller pattern (Figs. 8, 9). The nostrils are small, and near the muzzle : the orbits are circular, and separated by a space of more than their own diameter. In the upper jaw there is a series of con- ical teeth on the maxillary and intermaxillary bones (Figs. 5, 15). Those on the intermaxillaries are much larger than the others* and have the aspect of tusks or canines (Figs. 3, 13). Within this outer series of teeth, but implanted apparently in the same bones, there is as in Archegosaurus a second series of teeth, closely placed, or with intervals equal to the diameter of one tooth. These inner teeth are longer than the others, implanted in shallow sockets, to which they are anchylosed, and have the dentine plicated, except toward the point (Figs. 2, 4, 6, T, 17). A third group of teeth, blunt at the points, largely hollow in the in- terior, and with the dentine quite simple, appears in detached bones, which may represent the vomer (Fig. 12). Only a part of this formidable armature of teeth appears in the skull represented in Fig. 1, as the bones of the roof of the mouth have been removed, adhering to the opposite side of the matrix ; but the fact of the occurrence of two sets of teeth was ascertained by Prof Wyman, from the original specimens, and is manifest in the fragment AIR-BREATHERS OF THE COAL PERIOD. 21 represented in Fig. 17 ; while the other teeth, supposed to be vomerine, appear in fragments which must, from their size and collocation, have belonged to Dendrerpeton. It will be observed that all these teeth are anchylosed to the bone ; and that those of the vomer are thinly walled and simple, the outer series on the maxillaries and intermaxillaries simple and flattened, while the inner series of teeth are conical and plicated. In the lower jaw there was a uniform series of conical teeth, not per- ceptibly enlarged toward the front ; at least this is the case in the only specimen at present in my collection (Fig. 16) ; which is however merely an imperfect cast in hard sandstone. The scapular and sternal bones seem to have been well devel- oped and strong, but only portions of them are known (Fig. 25.) The fore limb of the adult animal, including the toes, must have been four or five inches in length, and is of massive proportions. The bones were hollow, and in the case of the phalanges the bony walls were thin, so that they are often found crushed flat. The humerus however was a strong bone, with thick walls and a can- cellated structure toward its extremities ; still even these have sometimes yielded to the great pressure to which they have been subjected. Fig. 26 shows the humerus of the original specimen of the species, and Fig. 10 exhibits a series of sections of a similar bone, probably the humerus of a smaller individual. The cavity of the interior of the limb-bones is usually filled with calc-spar stained with organic matter, but showing no structure ; and the inner side of the bony wall is smooth, without any indication of cartilaginous matter lining it. The vertebrae, in the external aspect of their bodies, remind one of those of fishes, expanding toward the extremities, and being deeply hollowed by conical cavities, which appear even to meet in the centre. There is however a large and flattened neural spine. The vertebrae are usually much crushed, and it is almost impos- sible to disengage them from the stone. Fig. 21 exhibits the usual form, and Fig. 22 another ; which, in its long neural and haemal spines, reminds us of the caudal vertebrae of those batrachians and 22 AIR-BREATHERS OF THE COAL PERIOD. reptiles which have tails flattened for swimming, and probably in- dicates that this was the case with Dendrerpeton. Fig. 23 is a transverse section of a somewhat crushed vertebra, showing its os- sified centrum and neural spine, and also the microscopic struc- ture of the bone. The ribs are long and curved, with an expanded head, near to which they are solid, but become hollow toward the middle ; and the distal extremities are flattened and thin walled. The posterior limb seems to have been not larger than the ante- rior, perhaps smaller. The bones represented in Fig. 27, which I refer to this member, probably belonged to a somewhat smaller individual than that to which the humerus in Fig. 26 belonged. The tibia is much flattened at the extremity, as in some labyrin- thodonts, and the foot must have been broad, and probably suited for swimming or walking on soft mud, or both. That the hind limb was adapted for walking is shown, not merely by the form of the bones, but also by that of the pelvis, the best preserved specimen of which is represented in Fig. 28 ; but an iliac bone of still larger size is figured in the Journal of the Geological Society, Vol. IX. The external scales are thin, oblique-rhomboidal or elongated- oval, marked with slight concentric lines, but otherwise smooth, and having a thickened ridge or margin ; in which they resemble those of ArcHegosaurus^ and also those ofPholidogasterpisciformis, recently described by Huxley from the Edinburgh coal-field, an animal which indeed appears in most respects to have a close affi- nity with Dendrerpeton. The microscopic structure of the scales is quite similar to that of the other bones, and different from that of the scales of ganoid fishes, the shape of the cells being batra- chian as in Fig. 11. Figs. 18 and 19 exhibit different forms of the scales. With respect to the affinities of the creature, I think it is ob- vious that it presents some points of resemblance, on the one hand to Archegosaurus, and on the other, to Labyrinthodon ; and that it has the same singular mixture of ichthyic, batrachian, and reptilian characters which distinguish these ancient animals, and which give them the appearance of prototypes of the reptilian AIK-BREATHERS OF THE COAL PERIOD. 23 class. Professor Owen regards ArcJiegosaurus as the type of the order Ganocephala, which he characterizes as having the head protected by sculptured and polished ganoid plates, no occipital con- dyles, teeth with converging folds of cement at their basal half, the notochord persistent, the ribs short and straight, the limbs natato- ry and small ; and holds that Dendrerpeton approaches more nearly to this order than to the Labyrinthodonts. But at the time when this opinion was expressed, he was not fully aware of the develop- ment of the limbs and ribs, and of the ossified condition of the vertebrae ; characters which, with the form of the skull, the ar- rangement of the teeth, and the probable possession of occipital condyles, appear to determine the scale in favour of the Labyrin- thodonts. At the same time it must be admitted that Dendrerpe- ton is far removed from the typical genus Lalyrinthodon, and that in the characters in which it differs, it leans toward Arche- gosaurus; closely resembling in thisits contemporary Pholidogaster pisciformis already referred to. This ancient inhabitant of the coal swamps of Nova Scotia, was, in short, as we often find to be the case with the earliest forms of life, the possessor of powers and structures not usually, in the modern world, combined in a single species. It was cer- tainly not a fish, yet its bony scales, and the form of its vertebrae, and of its teeth, might, in the absence of other evidence, cause it to be mistaken for one. We call it a batrachian, yet its dentition, the sculpturing of the bones of its skull, which were certainly no more external plates than the similar bones of a crocodile, its ribs, and the structure of its limbs, remind us of the higher reptiles ; and we do not know that it ever possessed gills, or passed through a larval or fish-like condition. Still, in a great many important char- acters, its structures are undoubtedly batrachian. It stands, in short, in the same position with the Lepidodendra and SigiUarice under whose shade it crept, which though placed by palseo-bota- nists in alliance with certain modern groups of plants, manifestly differed from these in many of their characters, and occupied a dif- ferent position in nature. In the coal period, th -distinctions of 24 AIR-BREATHERS OP THE COAL PERIOD. physical and vital conditions were not well defined dry land and water, terrestrial and aquatic plants and animals, and lower and higher forms of animal and vegetable life, are consequently not easily separated from each other. This is no doubt a state of things characteristic of the earlier stages of the earth's history, yet not necessarily so ; for there are some reasons, derived from fos- sil plants, for believing that in the preceding Devonian period there was less of this, and consequently that there may then have been a higher and more varied animal life than in the coal period.* Even in the modern world also, we still find local cases of this early union of dissimilar conditions. It is in the swamps of Africa, at one time dry, at another inundated, that such interme- diate forms as Lepidosiren occur, to baffle the classificatory pow- ers of naturalists ; and it is in the stagnant unaerated waters, half swamp, half lake or river, and unfit for ordinary fishes, that the semi-reptilian Amia and Lepidosteus still keep up the characters of their palaeozoic predecessors. The dentition of Dendrerpeton shows it to have been carnivo- rous in a high degree. It may have captured fishes and smaller reptiles, either on land or in water, and very probably fed on dead carcases as well. If, as seems likely, the footprints referred to in a previous section belong to Dendrerpeton, it must have fre- quented the shores, either in search of garbage, or on its way to and from the waters. The occurrence of its remains in the stumps of Sigillaria, with land-snails and millipedes, shows also that it crept in the shade of the woods in search of food ; and under the head of coprolitic matter, in a subsequent section, I shall show that remains of excrementitious substances, probably of this species, contain fragments attributable to smaller reptiles, and other animals of the land. All the bones of Dendrerpeton hitherto found, as well as those of the smaller reptilian species hereafter described, have been ob- * See the author's paper on Devonian plants, Journal of the Geological Society, Vol. xviii, p. 328. AIR-BREATHERS OF THE COAL PERIOD. 25 tained from the interior of erect Sigillariae, and all of these in one of the many beds, which, at the Joggins, contain such remains. The thick cellular inner bark of Sigillaria was very perishable ; the slender woody axis was somewhat more durable ; but near the surface of the stem, in large trunks, there was a layer of elon- gated cells, or bast tissue, of considerable durability, and the outer bark was exceedingly dense and indestructible. * Hence an erect tree, partly imbedded in sediment, and subjected to the in- fluence of the weather, became a hollow shell of bark ; in the bot- tom of which lay the decaying remains of the woody axis, and shreds of the fibrous bark. In ordinary circumstances such hol- low stems would be almost immediately filled with silt and sand, deposited in the numerous inundations and subsidences of the coal swamps. Where however they remained open for a consi- derable time, they would constitute a series of pitfalls, into which animals walking on the surface might be precipitated ; and being probably often partly covered by remains of prostrate trunks, or by vegetation growing around their mouths, they would be places of retreat and abode for land-snails and such creatures. When the surface was again inundated or submerged, all such animals, with the remains of those which had fallen into the deeper pits, would be imbedded in the sediment which would then fill up the holes. These seem to have been the precise conditions of the bed which has afforded all these remains, I may add that I be- lieve all the trees, four or five in number, which have become exposed in this bed since its discovery, have been ransacked for such remains ; and that while all have afforded some reward for the labour, some have been far more rich than others in their contents. It is also to be observed that owing to the mode of accumulation of the mass filling the trees, the bones are usually found scattered in every position, and those of different species intermingled; and that being often much more ^friable than the * See a paper by the author, on the structures of coal ; Journal of the Geological Society, Vol. xv ; also supplement to Acadian Geology. D 26 AIR-BREATHERS OF THE COAL PERIOD. matrix, much labour is required for their development ; while after all has been done, the result is a congeries of fragments like tjiat presented by Plate III. The two specimens which displayed the largest number of bones in juxtaposition, are one of Dendrerpeton Acadianum, and one ofHylonomus Lyelli, both presented by me to the geological Society oi London, and now in its collection ; but of which I shall endeavour to obtain accurate representations for this memoir. In order more fully to illustrate the mode of occurence of these remains, I quote the following notice of my last explorations in the bed containing them, from the Journal of the Geological So- ciety of London, for 1861 : " In the bed which has hitherto alone afforded reptilian re- mains in its erect trees, two additional examples of these were exposed. One was on the beach, and in part removed by the sea. The other was in the cliff, but so far disengaged that a miner succeeded in bringing it down for me. In the first, comparatively little was found. It afforded only a few shells of Pupa vetusta, and scattered bones of a full-grown individual of Dendrerpeton Acadianum. " The second tree was more richly stored ; and, being in situ, was very instructive as to the mode of occurence of the remains. Like all the other trees in which reptilian bones have been found, it sprang immediately from the surface of the six-inch coal in Group XV. of my section* ; which is also Coal No. 15 of Sir W. E. Logan's sectionf . Its diameter at the base was two feet, and its height six feet, above which, however, an appearance of additional height was given by the usual funnel-shaped sinking of the over- lying beds toward the cavity of the trunk. The bark is well pre- served in the state of bituminous coal, and presents externally a longitudinally wrinkled surface, without ribs or leaf-scars ; but within, on the * ligneous ' surface, or that of the inner bark, there * Quart. Journ. Geol. Soc.'Vol. ix. p; 58, and Vol. x. p. 20. t Reports of Geol. Surrey of Canada, 1845. AIR-BREATHERS OF THE COAL PERIOD. 27 are broad flat ribs, and transversely elongated scars. The ap- pearances are precisely those which might be expected on an old trunk of my Sigillaria Brownii ; to which species this tree may have very well belonged.]; " The contents of the trunk correspond with those of others pre- viously found. At the bottom is the usual layer of mineral char- coal, consisting of the fallen wood and bark of the tree itself. Above this, about two feet of its height are filled with a confused mass of ve- getable fragments, consisting of Cordaites, Lepidodendron, Uloden- dron, Lepidostrobus, Calamites, Trigonocarpum, stipes and fronds of ferns, and mineral charcoal ; the whole imbedded in a sandy paste blackened by coaly matter. In, and at the top of this mass occur the animal remains. The remainder of the trunk is oc- cupied with grey and buff sandstone, containing a few fragments of plants, but no remains of animals. " Portions of six reptilian skeletons were obtained from this trunk. The most important of these is a large and nearly complete skele- ton of Dendrerpeton Acadianum* Another specimen found in this trunk is a jaw of an animal about the size of Dendrerpeton Acadianum, but with fewer and larger teeth.f The remaining skeletons were imperfect^ and belonged to a small individual of Dendrerpeton Acadianum, two of Hylonomus Lyelli, and one of Hylonomus Wymani. The dislocated condition of these and other skeletons is probably due to the circumstance that, when they were introduced, the matter filling the trunk was a loose mass of fragments, into the crevices of which the bones dropped, on decay of the soft parts. Most of the skeletons lie at the sides of the trunk, as if the animals had before death crept close to the walls of their prison. At the time when the reptiles were intro- duced, the hollow trunk must have been a pit four feet in depth. J Quart. Journ. Geol. Soc. Vol. xrii. p. 523. * Now in the collection of the Geological Society of London. Fig. 1, represents the skull of this specimen, f Since named and described by Prof. Owen as Hylerpeton Dawsoni 28 AIR-BREATHERS OF THE COAL PERIOD. A number of specimens of Pupa vetusta and Xylobius Sigillarite were found, but nothing throwing further light on these species. " The beds on a level with the top of this erect tree are arena- ceous sandstones, with numerous erect Calamites. I searched the surfaces of these beds in vain for bones or footprints of the rep- tiles which must have traversed them, and which, but for the hol- low erect trees, would apparently have left no trace of their exis- tence. On a surface of similar character, sixty feet higher, and separated by three coals, with their accompaniments, and a very thick compact sandstone, I observed a series of footprints, which may be those of Dendrerpeton or Hylonomus? Through the kindness of the Council of the Geological Society of London, the fine skeleton of Dendrerpeton Acadianum, sent by me to the Society in 1861, has been returned for my inspection in the preparation of this article. I am now able to state, in addition to the facts already noticed that the large furrowed teeth of the inner series were not placed in the palatal bones, but on the maxillaries and intermax- illaries, the outer series of smaller and simple teeth being borne on the outer margin of these bones. The arrangement was thus somewhat similar to that in Lepidosteus. Immediately within the large teeth were the vomerine series, which were very numer- ous and irregularly placed, but small, with the exception of a few in front. They extended backward in two lines along both sides of the palate, in this also resembling some ganoid fishes. In this specimen, the lower jaw, remaining in place under the skull, is seen to contain, especially toward the front, long fur- rowed teeth like those of the upper jaw, implanted in round 'soc- kets on the broad upper surface of the mandible, with others more simple and of smaller size. By carefully removing the stone,! have uncovered the occipital condyles, which are double and square in outline, much like those of Ldbyrinihodon, and not dissimilar from those of Sieboldia and Menobranchus. AIR-BREATHERS OF THE COAL PERIOD. 29 Near the skull, the scales of the throat remain in their natural position, and are seen to be densely imbricated, and arranged in curved rows, diverging from the mesial line. The scales of the abdomen are of larger size, and are scattered over the stone. Those of the throat are of a narrow ovate form, those of the abdo- men wider, and some of them tending to rhomboidal in outline. Twenty-four vertebrae, in all, are seen in the specimen. Of these thirteen occur in continuous series, and appear to be lumbar. They are of small size, relatively to the dimensions of the head and limbs, and indicate a weak and flexible back. Other verte- bra, not in regular series, are dorsal, and have strong transverse processes with oblique articulating surfaces. A few are perhaps cervical and caudal. The bodies of the vertebra have continuous bony walls, but thinner than in specimens of larger size. One half of the pelvis is well preserved, and shows a broad ilium, and strong ischiac and pubic bones. There are also broad scapular, and probably sternal bones, but crushed and imperfect. Few of the ribs remain, and these apparently only the smaller ones, as compared with other skeletons of which I have portions. Several of the bones of the limbs remain in sufficiently good preservation to allow of measurement of their size. I am thus enabled to give the following dimensions of parts of the animal. Total length of skull, . 2-75 inches. " breadth " at the orbits, 2 " Length of humerus, 1*33 inch. " " ulna, 1 " " " femur, 1 " " rib, 0-T5 " " eleven vertebrae in series, 225 " It would seem from these dimensions that the head was broad, and the trunk slender; the anterior limb, including the foot, half as long again as the head, and the posterior limb rather smaller or shorter than the anterior. It would thus appear that while the general form of the body was not unlike that of Meno- branchus, the limbs were much larger, and must have carried the 30 AIK-BREATHERS OP THE COAL PERIOD. trunk without allowing any part of it to touch the ground, as would -also seem to have been the case from the footprints found in the coal-formation beds, and the size and form of the toes of which make it likely that they belonged to this animal. The limb-bones, though thin-walled atfd often crushed, evi- dently had broad articulating surfaces ; and in the case of the fore- limbs particularly, were large and strong in proportion to the di- mensions of the head and vertebral column. The large size of the fore-limb I suppose to have been related lo a habit of walking or standing in shallow water, with the snout in the air, in the manner of newts, and the more rapid movements of the creature were probably performed by the tail. It is inter- esting to observe that in Hylonomus the proportions of the limbs were reversed the hind limbs being much larger than the fore limbs. From the relative dimensions of the bones, as compared with those of other specimens in my possession, I presume that this in- dividual was three-fourths grown, and I doubt if its total length much exceeded one foot. EXPLANATION OP PLATE III. Dendrerpeton j&cadianum. Fig. 1. Skull seen from below. 2. Inner tooth, magnified ; from the jaw, Fig. 17. 3. Tooth of intermaxillary, magnified ; from the bone in Fig. 13. 4. Series of inner teeth, less magnified. 6. Series of outer teeth of maxillary bone, Fig. 15, magnified. 11 6, 7. Sections of inner teeth. M 8. Portion of bone of skull, outer surface, twice the natural size. 9. Super-temporal bone, twice the natural size. M 10. Cross section of humerus ; (a) natural size ; (b) magnified ; (c) portion more highly magnified, showing canals and bone cells. Perhaps increased by flattening. AIR-BREATHERS OP THE COAL PERIOD. 31 Fig. 11. Bone cells, highly magnified (after Quekett). 12. Vomer ? with teeth ; (a) tooth magnified. " 13. Intermaxillary with teeth. " 14. Section of tooth of intermaxillary ; (b) magnified ; (a) portion highly magnified. " 15. Maxillary bone with teeth. " 16. Mandible with teeth. 17. Fragment of skull, with (a) outer teeth of maxillary ; (b) in- ner teeth. 11 18. Cross section of a scale, magnified. " 19. Outlines of scales, natural size. " 20. Scale, twice natural size. 21. Vertebra. " 22. Caudal vertebra, " 23. Vertebra broken across, showing neural and central cavities ; (a) natural size ; (b) section of a portion magnified, showing canals and bone cells. tt 24. Fragments of ribs. " 25. Scapular bone. " 26. Humerus, crushed at the proximal end, with fragment of the radius. " 27. Fragments of femur, tibia, and fibula. 11 28. Remains of pelvis. 29. Bones of the foot. " 30. Group of bones of the foot, in situ. All the above are of the natural size, unless otherwise stated. 32 AIR-BREATHERS OF THE COAL PERIOD. V. DENDRERPETON OWENI. Plate IV. Among the reptilian remains found in erect trees at the South Joggins, there have occurred several portions of skeletons, which from their sculptured cranial bones, plicated teeth, and the forms of their scales and limb-bones, I have referred to the genus Den- drerpeton, but to individuals of much smaller size than the full- grown specimens of D. Acadianum. It did not occur to me to suppose that these were specifically distinct from the larger indi- viduals, until I observed that bones of this kind, contained in the collections sent by me to the Geological Society, or represented in the figures drawn to illustrate one of my papers, were referred by Professor Owen, in his notes on these specimens and figures, in the Journal of the Geological Society, to the genus Hylonomus ; which is quite distinct from Dendrerpeton, as will be explained in the sequel. I was thus induced to re-examine all the specimens in my col- lection, and the result has been to establish a strong probability that there is in reality a second species of Dendrerpeton, smaller than D. Acadianum^ and differing from it in several points. Thia species I propose to name JD. Oweni. It differs from D. Acadia- num in the following particulars : (1) Its much smaller size : (2) Its long and hooked teeth ; PI. IV, Figs. 2 to 8 ; (it will be seen that these teeth differ very markedly in their proportions and form from those of the larger species represented in PL III) : (8) The greater plication of the ivory in the intermaxillary teeth ; Figs. 8, 9 ; (in D. Acadianum these teeth are, on the outside, simple almost to the base, and plicated on the inner side, while in this species they are plicated all around like the inner maxillary teeth) : (4) The form of the skull, which has the orbits larger in proportion, and is also shorter and broader. On the other hand, when we have described the species of Hylonomus, it will be seen that this animal, except in size, differs from them quite as widely aa does D, Acadianwn. AIR-BREATHERS OF THE COAL PERIOD. 33 The distinctness of D. Oweni is further confirmed by the fact that I possess small jaw bones of Dendrerpeton, about the size of those of this species, but having the teeth similar in form to those of the larger species ; these I suppose to have belonged to young individuals. On examining the figures, it will be seen that the bones of the skull were corrugated as in the large Dendrerpeton, but with a smaller pattern. The forms of the jaw-bones also, and of the ver- tebrae, ribs, scapular bone, bones of the limbs, and bony scales, are very similar, and indicate that in general form this creature was not far removed from its larger relative. The bones of the foot, represented in Fig. 14, especially deserve attention. This is the most perfect foot of Dendrerpeton hitherto found ; and I have enlarged it in the figure, in order more distinctly to show its parts. It presents three long toes, with traces of a smaller one at each side, so that there were probably five in all. If these toes be compared with the footprints on the slab discovered by Dr. Hard- ing, represented in PI. I, Fig. 2, it will be seen that they very closely correspond, though the toes of the present species are much smaller. The footprints are precisely those which we may suppose an animal of the size of Dendrerpeton Acadianum would have made, if, as the bones found render in every way probable, this larger species had a foot similar to that of D. Oweni. I sup- pose, for this reason, that these footprints are really those of Den- drerpeton Acadianum} and that this species continued to exist from the time of the lower coal measures, to the period when those higher beds of the series, in which its bones are found at the Joggins, were deposited. The present species must have lived in the same places with its larger relative j but may have differed somewhat in its habits. Its longer and sharper teeth may have been better suited for de- vouring worms, larvae or soft-skinned fishes, while those of the larger Dendrerpeton were better adapted to deal with the mailed ganoids of the period, or with those smaller reptiles which were more or less protected with bony or horny scales. 34 AIR-BREATHERS OF THE COAL PERIOD. VI. REMAINS OF SKIN AND HORNY SCALES. Plate I, Pig. 5; Plate IV, Figs. 22 to 34, and Plate V, Figs. 22 to 29. In one of my earliest explorations of the reptile-bearing stumps of the Joggins, I observed on some of the surfaces, patches of a shining black substance, which on minute examination proved to be the remains of cuticle, with horny scales and' other appendages. The fragments were preserved ; but I found it impossible to deter- mine with certainty to which of the species whose bones occur with them they belonged, or even to ascertain the precise rela- tions of the several fragments to each other. I therefore merely mentioned them in general terms, and stated my belief that they may have belonged to the species of Hylonomus.* More recently other specimens have been obtained, and I have undertaken the detailed examination of the whole. I shall now endeavour to describe the principal or most continuous fragments, and after- ward to consider the probabilities of their having belonged to cer- tain of the reptiles entombed with them. I do this here, rather than under the titles of these several animals, on account of the uncertainty which still rests on the assignment of certain portions of this cuticle to the species in question, and which renders it more convenient to consider these peculiar remains in one place, and to compare the different portions with each other. (1) One of my specimens is a flattened portion of cuticle 2 J inches in length. The greater jpart of the surface is smooth and skining to the naked eye, and under the microscope shows only a minute granulation. A limited portion of the upper, and I sup- pose, anterior part is covered with imbricated scales, which must have been membranous or horny, and generally have a small spot or pore near the outer margin, some having in addition smaller scales or points on their surfaces, (PI. IV, Figs. 22 and 25). In contact with the upper part of this specimen there were many fragments of the skull of Dendverpeton Oweni. Journal of Geological Society, Vol. XYI. AIK-BREATHERS OF THE COAL PERIOD. 35 (2) Another portion of cuticle, similarly marked, appears to preserve the form of the posterior part of the body and tail of the animal, and also a mark representing the point of attachment of the hind leg ; near to which, and along the dorsal ridge, is a por- tion of the skin covered with much smaller scales. It is repre- sented in PL T, fig. 5. This was found in close proximity to a mass of bones of Dendrerpeton Oweni, mingled with some of Hy- lonomus Lyelli. (3) A third and still larger surface of integument with similar markings, has upon it a number of vertebrae and detached bones of the small reptile Hylonomus Wymani^ to be described in the sequel ; for which species however it would be much too large a covering. (4) Another well preserved fragment, less than two inches in length, exhibits very different markings. It is nearly covered with very small imbricated scales, thicker than those on the spe- cimens previously described. On either side of what seems to have been the middle line of the back, there is a series of pointed flat horny processes, which probably formed a double spinous crest. Without these there are tufts of strong bristles, and exteriorly to these last are rows of flat, thick, horny plates, transversely wrink- led. Near to these was a row of conical truncated tubercles. Sections of these appendages show them to have been horny and attached to the cuticle. None of them have bony structure. Figs. 23, 26, 27, 28, 29, 30, PI. IV, represent this portion of cu- ticle, with magnified views of its markings, and of the structure of one of the thicker scales. Fig. 26 shows a portion of the ordi- nary scaly skin magnified and viewed by transmitted light. Fig. 27 exhibits a few of the bristle-like appendages from the point marked a in fig. 23. Fig. 28 shows four of the bluntly-conical points seen in a portion of skin a little beyond the margin of the fragment in fig. 23, but evidently belonging to it. Fig. 24 is an enlarged representation of one of the flat horny scales from the point b in fig. 23 ; and fig. 29 is a magnified section of a por- tion of the same scale, showing a compact translucent brown 36 AIR-BREATHERS OF THE COAL PERIOD. substance with round canals, and near the margin, a portion much more abundantly supplied with these, apparently vascular canals, while without this part there is a thin layer of more dense mate- rial. Fig. 30 shows a portion of the surface of fig. 23, more highly magnified, and displaying at a ordinary scales, at b horny pointed organs, at c bristly appendages, and at d large plates. The whole of these parts, though displaced by the flat- tening and wrinkling of the skin, are in good preservation, and show their characters in great perfection under the microscope. They are all black and shining as if carved in jet. (5) Near this last portion of cuticle, and possibly belonging to it, are pointed and probably membranous appendages, marked on each side with rows of scales not overlapping, and each with a pore in its centre. The manner in which these appendages are bent and wrinkled, shows that they must have been soft, except at the tips, which seem to have been hard and horny, and they are arranged in series, as if originally placed along the sides of the neck or abdomen, or both. These appendages are represented in PL IV, figs. 31 and 32. A magnified representation of the point of one of them is given in fig. 33, and a small portion, stilJ more highly magnified, in fig. 34. The use of these appendages it is not easy to conjecture. They remind us of the gular pouches of iguana, and of the lateral expansions of some geckos and of the Draco volans* Possibly they formed lateral parachutes, aiding the animal in moving over soft mud, or perhaps in leaping or swimming. (6) Some other fragments appear to have belonged to a diffe- rent species from either of the foregoing, and are represented in PI. V. The best preserved specimen (Fig. 22), which is about one inch in length and half an inch in breadth, is covered with very small imbricated scales. It is crossed by six or seven obscure ridges, which both at the bottom and along a mesial line, pro- jected into points covered with larger scales. A row of large scales with round pores, connects these along the lower side (Figs. 23 and 24.) If, as seems probable, this fragment belonged to the AIE-BEEATHEES OP THE COAL PERIOD. 37 side of the trunk or tail, it would perhaps indicate a division of the sub-cutaneous muscles into an upper and lower band, as in the newts. A separate fragment, with transverse horny ridges (Figs. 26 and 27), and another with a longer lobe similar in structure to those above mentioned (Figs. 28 and 29), may perhaps be re- ferred to the same animal. A larger patch of skin presents simi- lar imbricated scales, but without a mesial line, and with an edg- ing of larger scales (Fig. 25). Six species of reptiles have left their bones in the repositories containing these remnants of cuticle. Of these, Dendrerpeton Aca- dianum was an animal of too great sigfc to have been clothed with integument of this character and of such dimensions. Hylo- nomus aciedentatus, described in Section VIII, and Hylerpeton Dawsoni, Section X, are each represented by only a single speci- men, and these did not occur in proximity to any of the portions of cuticle, except that the appendages in PI. IV, fig. 32, were found near a specimen of the former. Of the three remaining species, Dendrerpeton Oweni, from its size, the number of speci- mens found, and the juxtaposition of their bones to the fragments of cuticle, appears to have the best claim to the integument in- cluded under Nos. 1, 2, and 3 ; and in this case, while the crea- ture had its throat, and perhaps its abdomen, armed with bony scales, its upper parts and tail, as well as its limbs, had a uniform covering of small thin imbricated horny scales, in the manner of many modern reptiles. If the remaining portions of integument, Nos. 4 and 5, as would seem likely, belonged to two species, both of smaller dimensions, there would seem little reason to doubt that these were Hylono- mus Lyelli (Section VII) and H, Wymani (Section IX). In this case, both of these species must have possessed a highly or- nate covering of horny scales and appendages, comparable with that of any of the modern lizards, while there seems good reason to believe, as stated in a previous paper, that they were in part protected by bony scales somewhat like those of Dendrerpeton, These points, however, we shall consider more in detail under the sections which refer to the species of HylQnomus. 38 AIR-BREATHERS OF THE COAL PERIOD. Before leaving these curious specimens of ancient skin, the most ancient I suppose known to exist, it is of interest to observe that the thicker portions, when broken across, have the aspect of jet, or of pure shining coal, and that thin slices, under the microscope, have the same rich brown colour with that material, though rather more translucent. When burned, fragments of the substance give a strong flame, and a bituminous and ammoniacal odour. We have thus an example of the production of coal from animal mem- brane, no doubt gelatinous and horny in the first instance, but which has proved itself capable of the same chemical changes that have been experienced by the vegetable matter buried with it. In order that this substance should be preserved in this way, it would be necessary that it should either be kept dry and hard, or that it should be immediately buried in matter Impervious to air, and kept moist. The latter conditions are the more probable. The preservative qualities of the peaty vegetable matter imbedded with it must also be considered ; and it is possible that these hol- low stumps partly filled with fragments of Sigillaria bark, may have formed natural tan-pits, in which animal membranes would be preserved in a manner impossible in ordinary sediments. If this were the case, we may yet find an entire reptile, preserved as a flattened mummy, in one of these strange repositories. EXPLANATION OF PLATE IV. Dendrerpeton Oweni, and Dermal Appendages. Fig. 1. Skull. " 2. Portion of mandible. " 3. Maxillary bone, with outer teeth. " 4. Teeth of same enlarged. " 5. Maxillary bone, with inner teeth. 6. Tooth of same enlarged. ^ " Y. Intermaxillary. " 8. Tooth of same enlarged. M 9. Section of same enlarged. AIR-BREATHERS OF THE COAL PERIOD. 39 Fig. 10 and 11. Vertebrae. 11 12. Portion of pelvis. " 13. Fragments of ribs. " 14. Bones of foot enlarged, (a) natural size. " 15. Scapular bone. " 16. Humerus. " 17. Bones of hind leg. " 18 and 19. Sculpturing of cranial bones, enlarged. " 20. Bony scale. " 21. Socket of inner tooth enlarged. " 22 and 25. Integument of Dendrerpeton Oweni, with imbricated scales. " 23. Integument of Hylonomus Lyelli. 24, 26, 27, 28, 30. Scales and appendages of the same enlarged, " 29. Section of scale represented in Fig. 24. " 31. Angular pendants or processes of H. Lyelli. " 32. The same of H. aciedentatus. " 33 and 34. Portions of the same enlarged. 40 AIR-BREATHERS OF THE COAL PERIOD. VII. HTLONOMUS LTELLI. \ Plate V. In the original reptiliferous tree,discovered by Sir C. Lyell and the writer, at the Joggins, in 1851, there were, beside the bones of Den* drerpeton Acadianum,some small elongated vertebrae, evidently of a different species. , These were first detected by Prof. Wyman, in his examination of these specimens, and were figured, but not named, in the notice of the specimens in the Journal of the Geological Society, Vol. IX. In a subsequent visit to the Joggins, I obtained from another erect stump many additional remains of these smaller reptiles, and, on careful comparison of the specimens, was induced to refer them to three species, all apparently generically allied . I proposed for them the generic name Hylonomus, " forest-dweller." They were described in the proceedings of the Geological Society for 1859, with illustrations of the teeth and other characteristic parts.* The smaller species first described I named H. Wymani ; the next in size, that to which this article refers, and which was represented by a larger number of specimens, I adopted as the type of the genus, and dedicated to Sir Charles Lyell. The third and largest, represented only by a few fragments of a single skeleton, was named H. aciedentatus. Hylonomus Lyelli was an animal of small size. Its skull is about an inch in length, and its whole body, even if, as was likely, fur- nished with a tail, could not have been more than six or seven inches long. No complete example of its skull has been found. The bones appear to have been thin and easily separable j and even when they remain together, are so much crushed as to render the shape of the skull not easily discernible. They are smooth on the outer surface to the naked eye ; and under a lens show only delicate uneven striae and minute dots. They are more dense and hard than those of Dendrerpeton, and the bone-cells are more elongated in form. The bones of the snout would seem to have been Journal of Geological Society, Vol. XYI. AIR-BREATHERS OP THE COAL PERIOD. 41 somewhat elongated and narrow. A specimen in my possession shows the parietal and occipital bones, or the greater part of them, united and retaining their form. We learn from them that the brain-case was rounded, and that there was a parietal foramen. There would seem also to have been two occipital condyles ; (see plate V, fig. 8.). Several well preserved specimens of the maxillary and mandibular bones have been obtained. They are smooth, or nearly so, like those of the skull, and are furnished with numerous sharp, conical, teeth, anchylosed to the jaw, in a partial groove formed by the outer ridge of the bone. In the an- terior part of the lower jaw there is a- group of teeth larger than the others. The intermaxillary bone has not been observed. (Figs. 1, 2, 3, 4, 5, 6.) The total number of teeth in each ramus of the lower jaw was about forty, and the number in each max- illary bone about thirty. The teeth are perfectly simple, hollow within, and with very fine radiating tubes of ivory. (Fig. 7, a and b.) The vertebra? have the bodies cylindrical or hour-glass shaped, covered with a thin, hard, bony plate, and having within a cavity of the form of two cones, attached by the apices. This cavity was completely surrounded by bone, as it is filled with stained calc-spar in the same manner as the cavities of the limb bones. It' was probably occupied by cartilage. The vertebrae were apparently bi-concave. The neural spines are short and broad, with zygapophyses, and are not separable from the bodies, the neural arches being perfectly anchylosed to the bodies of the ver- tebrae. There are, on the dorsal vertebrae, strong diapophyses or lateral spines, to which the ribs were articulated. (Figs. 15, 16, 17.) The ribs are long, curved, and at the proximal end have a shoulder and neck. (Figs. 1, 10, 18.) They are hollow, with thin hard bony walls. The anterior limb, judging from the fragments pro- cured, seems to have been slender, with long toes, four or possibly five in number. A humerus is seen in fig. 1, and bones of the toes magnified in fig. 11. The posterior limb was longer and stronger, and attached to a pelvis so large and broad as to give the impression that the creature enlarged considerably in size toward P 42 AIR-BREATHERS OF THE COAL PERIOD. the posterior extremity of the body, and that it may have been in the habit of sitting erect. The thigh bone is well formed, with a dis- tinct head and trochanter, and the lower extremity flattened and moulded into two articulating surfaces for the tibia and fibula, the fragments of which show that they were much shorter. The toes of the hind feet have been seen only in detached joints. They seem to have been thicker than those of the fore foot. Detached vertebrae, which seem to be caudal, have been found, but the length of the tail is unknown. The limb bones are usually some- what crushed and flattened, especially at their articular extremities, and this seems to have led to the error of supposing that this flattened form was their normal condition ; there can be no doubt, however, that it is merely an effect of pressure. The limb bones present in cross section a wall of dense bone with elongated bone- cells, surrounding a cavity now filled with brown calc-spar, and originally occupied with cartilage or marrow. (Figs. 12, 13, 14.) Nothing is more remarkable in the skeleton of this creature than the contrast between the perfect and beautiful forms of its bones, and their imperfectly ossified condition, a circumstance which raises the question whether these specimens may not represent the young of some reptile of larger size. The dermal covering of this animal is represented in part by oval bony scales, which are so constantly associated with its bones that I can have no doubt that they belonged to it, being, perhaps, the clothing of its lower or abdominal parts ; while above,it was probably clad in the beautiful scaly covering described in the last sec- tion. The bony scales are represented magnified in Plate V. figs. 19. 20, and 21. It will be seen that they differ in form from those of Dendrerpeton ; they are also much thicker. On the inner side they are concave, with a curved ledge or thickened border at one edge. On the outer side they present concentric lines of growth. The only specimens which afford much information as to the general form of Hylonomus Lyelli are those represented in Plate V, figs. 1 and 9. The first is the original specimen, from which I described the species in the paper already referred to. The AIR-BREATHERS OF THE COAL PERIOD. 43 bones, being small and of dark colour, are not very conspicuous, and many of them are broken, but many are beautifully perfect ; and even those which are removed have left very distinct moulds of their form in the fine-grained matrix. In the figure I have carefully traced their outlines in their natural position, with the ex- ception of the maxillary bone and mandible, which are removed from their place in the matrix, to bring the whole into a more com- pact form. The specimen also shows, in addition to the bones delineated, many fragments of the skull and scapular bones, crushed in such a manner that their forms cannot be distinguished. The specimen shows remains of thirty vertebrae, of which four appear to belong to the neck, and the rest are probably nearly all dorsal and lumbar. Three of the most perfect are represented enlarged, in figs. 15 and 16. Of about twenty ribs, more or less complete fragments remain. The fore limb is represented only by the im- pression of a humerus, (e), but other bones which may have belonged to it are scattered elsewhere on the stone. The pelvis, (i) is nearly entire, though crushed and flattened. One thigh bone remains tolerably perfect, and beside it lie the tibia and a part of the fibula, with seyeral bones of the foot The dimensions of these parts are as follows : Length of maxillary O.T inch. " mandible 0.7 " " longest rib, (chord) 0.6 " humerus 0.5 " Length of femur , 0.7 inch. tibia 0.45" " principal bone of pelvis 0.7 " The other specimen above referred to, (Fig. 9.) shows the bones of the trunk, and part of those of the hind and fore limb of a small individual, nearly in their natural position. This specimen I have very recently obtained, in breaking open a mass of matrix in which I did not suspect its existence. It shows the humerus and radius and ulna in a tolerable state of preservation, with a fragment of the scapula. About thirteen dorsal and lumbar vertebrae can be 44 AIR-BREATHERS OF THE COAL PERIOD. made out, nearly in their natural position ; and there are remains of five of the ribs. The hind limb is represented by fragments of the femur, tibia, and fibula. I believe that the maxillary repre- sented in fig. 3, though now in a detached piece of stone, belonged to this skeleton. While referring to these, my most perfect specimens, I think it proper to quote my original description of the species, based on the first of them, and published in 1859 ; as the subject has since been unfortunately obscured by inaccurate descriptions, consequent on the mixture of specimens and drawings, sent by me to London for further examination. I quote from the journal of the Geolo- gical Society, Vol. XVI. " HYLONOMUS, gen. nov." " The other reptilian remains represent three species belonging to a generic form, which, so far as I am aware, has not been pre- viously observed, and for which, in allusion to its forest habitat, I propose the above name. As its typical species I. shall describe that which I would name Hylonomus Lyelli. Its cranial bones are thin and smooth ; the condyle I have not been able to observe, but there is a parietal foramen, and the parietal bones are arched in such a manner as to indicate a rounded rather than flattened skull, and a somewhat capacious brain-case. Its teeth are nume- rous (about twenty-six in each maxillary bone), elongated, conical, closely set in a single series, in a furrow, protected externally by an elevated alveolar ridge. In the intermaxillaries and extremities of the mandibles the teeth are larger than elsewhere. Fig. 14, (Fig. 5, Plate V. of this paper) represents a portion of the teeth of the maxillary bone as exposed by the fracture of the outer ridge. The vertebrae are imperfectly preserved, but appear to have been ossified, bi-concave, and with well-developed spinous processes. The ribs are long and curved ; and there are traces of numerous acces- sory pieces which have been attached to their extremities. The pelvis is of large size and remarkable form ; the ilium long and expanded below ; the ischium greatly expanded ; the pubis ex- AIR-BREATHERS OF THE COAL PERIOD. 45 paneled and triangular where it joins the ischium, and round and arched toward the symphysis. The femur is thick and nearly straight, the tibia short and stout, the fibula slender, the phalan- ges broad. The hind limb thus largely developed must have been capable of supporting the whole weight of the body in standing or leaping. The anterior extremities appear to have been compara- tively slender, with thin and long fingers. A few scattered verte- bra? lying posteriorly to the pelvis, may perhaps be remains of a tail. There was a dermal covering of small ovate bony scales, of which, however, only a" few scattered specimens remain. This species is evidently quite remote from the ganocephalous and laby- rinthodont types of batrachians, and in many respects approaches to lacertians. It may perhaps be allied to the Telerpeton of Elgin, but does not appear to resemble any reptile hitherto found in the coal-formation." It is evident, from the remains thus described, that we have in Hylonomus Lyelli an animal of lacertian form, with large and stout hind limbs, and somewhat smaller fore limbs, capable of walk- ing and running on land ; and though its vertebrae were imperfectly ossified externally, yet the outer walls were sufficiently strong, and their articulation sufficiently firm, to have enabled the creature to erect itself on its hind limbs, or to leap. They were certainly pro- portionally larger and much more firmly knit than those of Den- drerpeton. Further, the ribs were long and much curved, and im- ply a respiration of a higher character than that of modern batrachians, and consequently a more highly vitalized muscular system. If to these structural points we add the somewhat rounded skull, indicating a large brain, we have before us a creature which, however puzzling in its affinities when anatomically considered, is clearly not to be ranked as low in the scale of creation as modern tailed batrachians, or even as the frogs and toads. We must add to these also, as important points of difference, the bony scales with which it was armed below, and the ornate apparatus of horny appendages, with which it was clad above. These last, as described in the last section, and illustrated in Plate IV., shew that this little 46 AIR-BREATHERS OF THE COAL PERIOD. animal was not a squalid, slimy dweller in mud, like Menobranchus and its allies, but rather a beautiful and sprightly tenant of the coal-formation thickets, vying in brilliancy, and perhaps in colour- ng, with the insects which it pursued and devoured. Remains of as many as eight or ten individuals have been obtained from three erect sigillariae, indicating that these creatures were quite abun- dant, as well as active and terrestrial in their mode of life. With respect to the affinities of this species, I think it is abun- dantly manifest that it presents no close relationship with any rep. tile hitherto discovered in the Carboniferous system. The only in- dications of which I am aware of animals of this age, likely to be of similar type, are certain vertebrae discovered by Mr. Wheatley and Dr Newberry, in the coal formation of Ohio, and described, but not named, by Prof. Wyman, in Silliman's Journal, Vol. XXV, in connection with the singular bratrachian named by him Rani- ceps Lyelli ; which, in its broad frog-like head and want of ribs, differs materially from the creature now under examination. It is scarcely necessary to say that the characters above described, and illustrated by the figures in Plate V, entirely remove this ani- mal from Archegosaurus and Labyrinthodon, as well as from all the other creatures associated with them in the orders G-ano- cephala and Labyrinthodontia of Owen. Equal difficulties attend., the attempt to place it in any other group of recent or ex- tinct batrachians or proper reptiles. The structures of the skull, and of some points in the vertebrae, certainly resemble those of batra- chians ; but on the other hand, the well-developed ribs, evidently adapted to enlarge the chest in respiration, the broad pelvis, and the cutaneous covering, are unexampled in modern batrachians, and assimilate the creature to the true lizards. I have already, in my original description above quoted, expressed my belief that Hylonomus may have had lacertian affinities, but I do not desire to speak positively in this matter ; and shall content myself with stating the following alternatives as to the probable relations of these animals. (l)They may have been true reptiles of low type, and with batrachian tendencies. (2) They may have been repre- AIR-BREATHERS OF THE COAL PERIOD. 47 sentatives of a new family of batrachians, exhibiting in some points lacertian affinities. (3) They may have been the young of some larger reptile, too large and vigorous to be entrapped in the pit-falls presented by the hollow Sigillaria stumps, and in its adult state losing the batrachian peculiarities apparent in the young. Whichever of these views we may adopt, the fact remains, that in the structure of this curious little creature we have peculiarities both batrachian and lacertian, in so far as our experience of modern animals is concerned. It would however accord with observed facts in relation to other groups of extinct animals, that the primi- tive batrachians of the coal period should embrace in their struc- tures, points in after times restricted to the true reptiles. On the other hand, it would equally accord with such facts that the first- born of lacertians should lean toward a lower type, by which they may have been preceded. My present impression is, that they may constitute a separate family or order, to which I would give the name of MICROSAURIA, and which may be regarded as allied, on the one hand, to certain of the humbler lizards, as the Gecko or Agama, and, on the other, to the tailed batrachians. It is likely that Hylonomus Lyelli was less aquatic in its habits than Dendrerpeton. Its food consisted, apparently, of insects and similar creatures. The teeth would indicate this, and near its bones there are portions of coprolite, containing remains of insects and rnyriapods. It probably occasionally fell a prey to Dendrerpeton, as bones, which may have belonged either to young individuals of this species or to its smaller congener H. Wymani, are found in lar- ger coprolites, which may be referred with probability to Dendrer- Acadianum. 48 AIR-BREATHERS OP THE COAL PERIOD. EXPLANATION OF PLATE V. Hylonomus Lyelli, and Dermal appendages. Fig. 1 .Remains of a skeleton of a large individual of Hylonomus Lyelli ; (a) Maxillary; (6) Mandible; (c) Ribs; (d) Vertebrae 5 (e) Humerus; (/) Femur; (g) Tibia; (A) Fibula, (0 Pelvis ; (fc) Foot. " 2. Right Mandible. *n\ 3. Maxillary. \^ 4j 5. Portions of Maxillary, magnified. 6. Extremity of Mandible, magnified. 7. Sections of teeth ; (a) magnified, (6) highly magnified. " 8. Portion of cranium, magnified ; (a) natural size, (6) transverse section. " 9. Skeleton of the trunk of a small individual of H. Lyelli; (a) Fore limb, (6) Hind limb, (c) Ribs. " 10. Ribs from the slab, Fig. 1, magnified. " 11. Fore foot, magnified ; (a) natural size. " 12. Cross section of flattened femur, magnified. " 13, 14. Portions of the bone of the same, more highly magnified. " 15. Pair of Vertebrae (dorsal), magnified. 16. Vertebra magnified. 1 7. Vertebra broken across and magnified, showing (a) neural arch, (6) diapophysis, and (c) central cavity. " 18. Head of a rib, magnified. " 19, 20,21. Bony scales, magnified, (a) natural size. " 22. Portion of cuticle, probably of Hylonomus Wymani. " 23, 24. Parts of the same magnified. " 25. Lower margin of another portion of cuticle, magnified. " 26, 27. Ridged horny scale, natural size and magnified. " 28, 29. Cutaneous lobe, natural size and magnified. AIR-BREATHERS OF THE COAL PERIOD. 49 VIII. HYLONOMUS ACIEDENTATUS. Plate VI, Figs. 1 to 16. This species is founded on a single imperfect specimen obtained by me at the Joggins in 1859, and described in the Journal of the Geological Society, Vol. XVI. In this description, I men- tioned, as probably belonging to this species, certain detached bones which I have since found reason to attribute to Den- drerpeton Oweni. These did not however materially interfere with the characters of species, which I shall give here from the fragments represented in Plate VI, Figs. 1 to 16, and which occur together in the matrix in such a manner as to render it certain that they belonged to the same individual. In size, H. aciedent&tus was about twice as large as the species last described. Its teeth are very different in form. Those on the maxillary and lower jaw are stout and short, placed in a close and even series on the inner side of a ridge or plate of bone. Viewed from the side they are of a spatulate form, and pre- sent a somewhat broad edge at top as in Fig. 4. Viewed in the opposite direction, they are seen to be very thick in a direc- tion transverse to that of the jaw, and are wedge-shaped as in Fig. 5. There are about forty on each side of the mandible, and about thirty on each maxillary, as seen in Figs. 1, 2, and 3, of which the two first are magnified slightly, the last natural size.* Since the publication of my previous paper, I have ascertained that the intermaxillary bones bore teeth of the form represented in Fig. 6. They are larger than the others, thick and coming to a blunt point, which is seamed with longitudinal and slightly spiral ridges* This singular tooth must have been a most effi- cient instrument for crushing and penetrating the coats of crusta- ceans and insects, or the bony armour of the smaller ganoid fishes. Remains exist at the extremity of the lower jaw, which show that * In Prof. Owen's paper, J.G.S., Vol. 18, this bone is figured, but in- correctly stated to be twice natural size, and referred to H. Lyelli. a 50 AIR-BREATHERS OF THE COAL PERIOD. a few teeth there also were larger than the others, but whether they differed in form cannot be determined. The pulp cavity of the teeth is less extensive in proportion than in H. Lyelli, and the structure in the cross section is simple, showing merely radiating ivory tubes, as in Fig. 7. The bone represented in Fig. 8, was found with these remains, and as it is too large for the last spe- cies, and different from anything known in Dendrerpeton, it pro- bably belongs to the creature now under consideration. It is thin and smooth, except at the upper margin, where it has in the centre a group of small conical teeth. It evidently belongs to the palate, and somewhat resembles the palatal bone of Meno- Iranchus, but is broader, and the latter has no teeth. Detached fragments of the skull show that its bones were thin and dense and smooth on the surface as in H. Lyelli. That represented in Fig. 9 would seem to be a frontal bone seen from the inside. The remains of H. aciedentatus are too scanty to warrant much certain inference as to its form. Its vertebrae would seem to have resembled those of H. Lyelli, but to have been elongated and more thoroughly ossified (Fig. 16). Its ribs are similar in form and proportion to those of the last named species (Figs. 10 and 11). A pelvic bone and some detached phalangial bones (Figs. 12 and 13) as well as very fragmentary limb bones, would indicate that its limbs were well developed. Its external scales are similar to those of the last species but larger, and a few frag- ments of skin show scales and appendages similar to those of H. Lyelli, but of greater dimensions (Figs. 15 and 62). The micros- copic structure of its bone is also similar to that in the last species (Fig. 17). No doubt a more perfect specimen would show many points of difference between these species, not now appreciable ; but in the mean time the very different form of the teeth is a sufficient distinction. In H. Lyelli these are conical and pointed. In the present species they are of a peculiar wedge shape their diameter transversely to the jaw being the greatest at the base, while at the top they are sharpened to an edge. The peculiar form of the intermaxillary teeth may also serve as a distinctive AIE-BEEATHEES OF THE COAL PEBIOD. 51 character, though those of H. Lyelli are not yet known. The form of the vertebrae would further seem to indicate different pro- portions of body. On the whole, while this species is in all pro- bability generically related to the last, it is certainly specifically distinct. Its habits and food may have been similar, but its den- tal apparatus was stronger and more formidable. EXPLANATION OF PLATE VI, FIGS. 1 TO 16, AND FIG. 62. Hylonomus aciedentatus. Fig. } 1 Maxillary bone, magnified, (a) natural size. " 2 Mandible magnified, (a) natural size. " 3 Portion of mandible, natural size. " 4 and 5 Tooth, seen from the side and front. 6 Tooth of intermaxillary. " T Cross section of tooth, magnified. " 8 Palatal bone with teeth. 9 Frontal bone. " 10 and 11 Rib natural size and cross section enlarged. " 12 Pelvic bone. " 13 Phalangial bone. " 14 and 15 Bony scales magnified. " 16 Broken vertebra. " 62 Portion of skin with horny scales. 52 AIR-BKEATHERS OF THE COAL PERIOD, IX. HYLONOMUS WYMANI. Plate VI, Figs. 18 to 31. This is the species of ffylonomus originally detected by Pro!. Wyman in the specimens brought from the Joggins by Sir Cr Lyell and myself. Remains of several additional individuals have since been found, but no skeleton approaching to completeness. I shall describe this the most diminutive of the reptiles of the Nova Scotia coal, with the aid of the fragments represented in Plate VI, Figs. 18 to 31, most of which are almost microscopic in size. The skull seems to have been much of the same form as in Hy- lonomus Lyelli, but very thin and delicate, so that all the speci- mens hitherto found are crushed and fragmentary. The maxil- lary and mandibular bones are furnished with teeth which are bluntly conical in form, and in the latter bone seem to be confined to its front part, or to be very small posteriorly. They are thus much fewer in number than in th species last named. I have been able to make out only 22 in the lower jaw, and they are alternately large and small, as if replaced in this manner as worn out. Their structure is of the same simple character as in the other species of ffyknomm, and they have large pulp cavities. The vertebrae of this species are singular and characteristic. The bodies are elongated and hour-glass shaped, with an internal cavity of the same form rilled with calc spar (Fig. 30), and pro- bably once occupied by cartilage. They have, in the dorsal re- gion at least, strong articulating and lateral processes, and were furnished with numerous delicate ribs (Figs. 24, 25, 27); In one of my specimens as many as 38 of these little vertebrae may be seen lying together, and many of them attached to each other. This would indicate that the body was long and slender. It was furnished with limbs, similar to those of H. Lyelli, but very small and slender. The pelvis is of the same expanded form with that of the last species, and a pair of fore feet lying together on one slab, show the remain* of four slender toes (Fig. 29). The bones of the limbs are very delicate and thin walled (Fig. 26). The AIR-BREATHERS OF THE COAL PERIOD. 53 bony scales are oval, and similar to those of the other species of the genus, but very small (Fig. 31). I suppose it probable that the fragments of skin with imbricated scales represented in Plate .V, Figs. 22, 23, and 24, may have belonged to this species, but I cannot certainly affirm that this was the case. In length, ffylonomus Wymani could not have exceeded four or five inches, and its form was thin and slender. It may be questioned whether this little creature was not the young of one of the other species. The form of the vertebrae and teeth would y I think, prevent us from supposing that it stood in this rela- tion to H. Lyelli. To H. adedentatus it bears a stronger resem- blance in these respects, though not sufficient to render specific identity probable ; and the occurrence of so many specimens of the smaller species, without any of intermediate size, renders it likely that it did not attain to any greater dimensions. ffylonomus Wymani probably fed on insects and larvae, and searched for these among the vegetable debris of the coal swamps, which would afford to a little creature like this abundant shelter. It occasionally fell a prey to its larger reptilian contemporaries ; for quantities of its tiny bones occur in coprolitic masses probably attributable to Dendrerpeton. It is interesting to find reptilian life represented at this early period, not only by large and formi- dable species, but by diminutive forms, comparable with the smal- lest lizards and newts of the modern world. The fact is parallel with that of the occurrence of several small mammalian species in the mesozoic beds. It will be still more significant in this res- pect if the species of Hylonomus should be found to be truly la- certian rather than batrachian. 54 AIR-BREATHERS OF THE COAL PERIOD. EXPLANATION OF PLATE VI, FIGS. 18 TO 31. Hylonomus Wymani. Fig. 18 Lower jaw with teeth, magnified. " 19 Anterior part of lower jaw more magnified. " 20 Portion of maxillary bone with teeth, magnified. " 21 Maxillary bone, natural size. " 22 Lower jaw, natural size. 11 23 Vertebrae, natural size. " 24 and 25 Vertebrae, magnified. " 26 Humerus, natural size and magnified. " 27 Rib, natural size and magnified. " 28 Pelvic bone, natural size and magnified. 29 Foot ; the line shows the natural size. 30 Broken vertebra magnified, showing internal cavity. " 31 Bony scales, natural size and magnified. AIR-BREATHERS OP THE COAL PERIOD. 55 X. HYLERPETON DAWSONI. Plate VI, Figs. 32 to 46. In the more or less laminated material which fills the interior of the erect trees of the Joggins, it often happens that the more distinctly separable surfaces are stained with ferruginous or coaly matter, or with fine clay, so that the fossils which occur on these surfaces, and which would otherwise be more available than those in more compact material, are rendered so obscure as readily to escape observation. This was unfortunately the case with one of the most interesting specimens contained in the last of these trees which I had an opportunity to examine. It consisted of the de- tached bones of a reptile scattered over a surface so blurred and stained that they escaped my notice until most of them were lost ; and I was able to secure only a jaw bone and fragments of the skull, with a few of the other bones. On these fragments Prof. Owen founded 'the genus Hylerpeton and the species named at the head of this article. His description is as follows : " This specimen consists of the left ramus of a lower jaw (Fig. 32), which has been dislocated from the crushed head, of which the fore end of the left premaxillary is preserved, terminating near the middle of the series of the teeth of the more advanced mandible. A fragment of the left maxillary, which has been se- parated from the premaxillary, overlaps the hinder mandibular teeth. The fore part of the mandible is wanting. The teeth in the remaining part are larger and fewer, in proportion to the jaw- bone, than in Hylonomus or Dendrerpeton. They have thicker and more obtusely terminated crowns ; they are close-set where the series is complete at the fore part of the jaw, and their base appears to have been anchylosed to shallow depressions on the alveolar surface. The shape of what is preserved of the upper jaw affords the only evidence, and not very decisively, that the present fossil is not part of a fish. It inclines the balance, how- ever, to the reptilian side ; and, accepting such indication of the 56 AIR-BREATHERS OF THE COAL PERIOD. class-relations of the fossil, it must be referred to a genus of Rep- tilia distinct from those it is associated with in the Nova Scotian coal, and for which genus I would suggest the term Hylerpeton. " A small part of the external surface of the dentary bone shows a longitudinally wrinkled and striate or fibrous character. The outer bony wall, broken away from the hinder half of the dentary, shows a large cavity, now occupied by a fine greyish matrix, with a smooth surface, the bony wall of which cavity has been thin and compact. We have here the mark of incomplete ossifica- tion, like that in the skeleton of Archegosaurus. The crushed fore part of the right dentary bone, with remains of a few teeth, is below the left dentary, and exemplifies a similar structure. The teeth slightly diminish, though more in breadth than length, towards the fore part of the series : here there are nine teeth in an alveolar extent of 10 millimeters, or nearly 5 lines. The base of the teeth is longitudinally fissured, but the fissures do not ex- tend upon the exserted crown. In their general characters, the teeth manifest at least as close a resemblance to those of Gano- vephala as of Lacertia or any higher group of Reptilia ; whilst their mode of implantation, with the structure and sculpturing of the bone, weigh in favour of its relations to the lower and earlier order of the cold-blooded Vertebrates." I can add to the above description only a few facts obtained from careful examination of other fragments imbedded in the ma- trix. One of these is a portion of a maxillary bone (Fig. 32). It has teeth similar to those of the lower jaw in form (Figs. 34 and 35), but the last but one is twice the size of the others, and seems to have been implanted in a deep socket. All of the teeth have large pulp cavities, and the inner surface of the ivory is marked with slight furrows which are represented by ridges on the outer surface of the stony matter filling the pulp cavities (Fig. 36). The ivory of the teeth, however, which is very much coarser than that of the species of Hylonomus, presents in the cross section a simple structure of radiating tubes (Fig. 37). The surface of the cranial bones, of which some fragments remain, is AIR-BREATHERS OF THE COAL PERIOD. 57 marked in the same striate manner alluded to above by Prof. Owen (Figs. 42, 43). The microscopic structure of the bone is muca coarser than that of Hylonomus or Dendrerpeton, the cells being larger and in some portions less elongated (Fig. 46). That the creature had stout ribs is shown by the fragments represented in Fig. 40 ; but the vertebrae are represented only by a few bodies of small relative size and perhaps caudal (Figs. 38 and 39). On the same surface was found the foot represented in Fig. 44. It is of small size relatively to the head, and was probably for swim- ing rather than walking. A few ovate bony scales were found with the bones, and probably belonged to this species (Fig. 41). On the whole it seems certain that Hylerpeton must have been generically distinct from the other reptiles found with it, and it is probable that it was of more aquatic habits, swimming rather than walking ; and feeding principally on fish. More perfect speci- mens would however be required in order to warrant any decided statement on these subjects. It is possible, as suggested by Prof. Owen, that the affinities of the animal may be with Archegosau- rus rather than with any of the other coal reptiles ; but I confess that my present impression is that it tends rather toward the genus Hylonomus. It may possibly be a link of connection b- tween the Microsauria and the Archegosauria. EXPLANATION OF PLATE VI, FIGS. 32 TO 46. Hylerpeton Dawsoni. Fig. 32 Portion of maxillary bone with teeth. c 33 Lower jaw and portions of skull. " 34 and 35 Teeth magnified. (( 36 Cast of pulp cavity of a tooth. it a? Cross section of tooth magnified. 38 and 39 Bodies of Vertebrae. K 40 Fragments of ribs. 41 Bony scale natural size and magnified. " 42 and 43 Surface of bone magnified. 44 Foot. " 45 Bone of same magnified. 46 Section of bone highly magnified, H 58 AIR-BREATHERS OP THE COAL PERIOD, t XL ADDITIONAL REPTILIAN REMAINS. Plate VI, Figs. 47, 48, and 54 to 56. Beside the species above described, Mr. 0. 0. Marsh, in 1861,* added a new animal to the Joggins reptilian fauna ; the Eosau- ru Acadianus. The species is founded on two large biconcave vertebrae, in many respects resembling those of Ichthyosaurus, and indicating a reptile of greater size than any hitherto dis- covered in the coal, probably of aquatic habits, and possibly allied to the great Enaliosaurs or sea lizards of the mesozoic rocks. The specimen was found in a bed of shale belonging to group XXVI of my Joggins section, in the upper part of the middle coal measures, and about 800 feet above the bed which has afforded the remains described in previous sections. The beds belong to one of those intervals of shallow water deposition of sediment, which separate the groups of coal beds ; and on one of them I found some years ago the footprints of Dendrerpeton. The vertebrae of Eosaurus have been fully and ably described by Mr. Marsh in Silliman's Journal. Agassiz and Wyman regard their affinities as enaliosaurian. Huxley suggests the possibility, founded on his recent discovery of Anthrdcosaurus Russelli, that there may have been I/abyrinthodont batrachians in the coal pe- riod with such vertebrae. However this may be, if the vertebrae were caudal as supposed by Mr. Marsh, since they are about 2$ inches in diameter, they would indicate a gigantic aquatic reptile, furnished with a powerful swimming tail, and no doubt with appa- ratus for the capture and destruction of its prey, comparable with that of Ichthyosaurus. In a bed of hard calcareous sandstone, some distance below that which afforded the animal just noticed, there occur great numbers of teeth and scales, referable in part to large sauroid fishes, but perhaps also in part to reptiles. One of these is a remarkable tooth obtained by Sir W. E. Logan in 1843, and represented in * The remains were discovered in 1855 though not published till 1861 . AIK-BREATHERS OF THE COAL PERIOD. 59 Fig. 47. It resembles externally the teeth of Baphetes, but its structure is almost precisely that of the teeth of the Lepidosteus, or bony pike of the St. Lawrence. Another tooth from the same bed, and wfth a similarly fluted surface, has a more complex laby- rinthic structure, as seen in Fig. 48, which however represents only a small fragment. With these occur large round thin scales like those of Rhizodus, but also wrinkled bony plates resembling that which I have attributed to Baphetes. From the hardness of the rock it is difficult to extract perfect specimens of these re- mains, and no bones other than teeth and dermal scales have been found. Under this head may be noticed the coprolitic matter which not infrequently occurs with the remains of reptiles, in the erect trees of the Joggins, and to which reference has already been made in previous sections. This fossil excrement is of a brown or fawn colour, and consists in great part of carbonate, of lime, indicating probably that shells of snails or other mullusks formed a considerable part of the food of the smaller reptiles of the coal swamps. Some portions of it are rilled with small bones appa- rently of Hylonomus Wymani. Other examples contain abun- dance of fragments of chitinous matter referable ia part to Xylo- bius Sigillarice, the millipede of the coal ; and in other instances to insects. Of the latter kind of remains the most interesting is an Eye, represented in Fig. 56. It must have belonged to an in- sect of considerable size, and with highly complex eyes, probably a neuropterous insect. As many as 250 facets are distinguishable in the fragment preserved, and the whole number in each eye may have amounted to 2000. In size and form the facets re- semble those of the eye of a common Canadian dragon fly of the genus Aeschna, but are a little smaller. In this and other copro- lites, though abundance of minute chitinous fragments remain, no others are sufficiently perfect to be recognized. In one coprolitic mass a quantity of thick crust or shell occurs, which under the microscope presents a minutely tubular and laminated appear- ance, resembling that of the shell of a crustacean rather than 60 AIR-BREATHERS OF THE COAL PERIOD. any other kind of structure with which I am acquainted. There may have been laud-crabs in the coal period ; but it is perhaps more likely that some one of the larger individuals of Dendrer- peton had been feeding on crustaceans in some poUd or creek, before it fell into the pit in which it was entombed. It is how- ever interesting to observe that no remains whatever of fishes have occurred in any of this coprolite or in the erect trees contain- ing reptile bones, though such remains are very abundant in some of the associated beds. This fact confirms the inference dedu- cible from other considerations, that the ground in which these open pits presented themselves, was not that of a very low swamp, liable to inundation, or very near to the sea or other bodies of water. I may notice here certain very remarkable impressions, the origin of which I am at a loss to conjecture, but which may have had some relation to reptiles of the Coal period. They occurred on the surface of a layer of grey sandstone about 60 feet above the bed containing the erect reptiliferous trees. This bed is one of a series of flaggy layers on which occur, with vegetable frag- ments, tracks, possibly of Hylonomus, and rain-marks. The im- pressions now referred to were thus described by me in 1861 : " They consist of rows of tranverse depressions, about an inch in length and one-fourth of an inch in breadth. Each trail con- sists of two of these rows running parallel to each other, and about six inches apart. Their direction curves abruptly, and they sometimes cross each other. From their position they were pro- bably produced by a land or fresh-water animal possibly a large Crustacean or gigantic Annelide or Myriapod. In size and gene- ral appearance they slightly resemble the curious Climactichnites of Sir W. E. Logan, from the Potsdam sandstone of Canada." To this I have only to add that the space between the rows of marks is slightly depressed and smoothed, as if with a heavy body, like that of a serpent, trailed along. I have given in Fig. 54, as a supplement to the history of Den- drerpeton and Hylonomus, a diagram of the form of the skull and AIR-BREATHERS OF THE COAL PERIOD. 61 the character of the dentition, restored from actual specimens. This will serve further to illustrate the descriptions in previous sections. In Fig. 65 I have represented a group of scales from the throat of Dendrerpeton, as they lie beside the skull from which the greater part of the details in Fig. 54 are taken. It will be seen that these are elongated, oval, and very closely imbricated in rows diverging in a pinnate manner from a mesial line. They would give much protection, while not deficient in flexibility. It is pro- bable however that Dendrerpeton could breathe by other means than the gulping of air by the contraction of the throat ; and would therefore be less dependent on the action of the gular mus- cles than the modern batrachians. EXPLANATION OF PLATE VI, FIGS. 47, 48, AUD 54 TO 56.] Additional Reptilian Remains. Fig. 47 Tooth of unknown reptile or fish, natural size, section natu- ral size, and portion of section magnified, showing infold- ing of the enamel and arrangement of the dentine. 48 Small segment of another tooth similar to the last in form and size, but more complex in the folding of the enamel- 54 Outer figure Diagram of skull of Dendrerpeton, showing its size and general form, the appearance of the occipital condyles, and the arrangement of the double row of max- illary teeth and of the vomerine teeth. " 54 Inner figure Diagram of skull of Hylonomits, showing the arrangement of the single row of maxillary teeth and the patch of palatal teeth. 55 Bony scales of the throat of Dendrerpeton Acadianum, natural 62 AIR-BREATHERS OP THE COAL PERIOD. XII. INVERTEBRATE AIR-BREATHERS. Plate VI., Pigs. 49 to 53, and 56 to 61. In addition to the insect whose eye has already been noticed, but two species of land Invertebrates have been recognized in the coal of Nova Scotia. One of these is a snail, Pupa vetusta, the other a gally-worm or millepede, XyloHus sigillarice. They are represented in the figures referred to at the head of this section, and have been fully described in the Journal of the Geological Society of London. The first is the oldest known representative of the land snails, and so closely resembles the modern "chrysalis shells" of the genus Pupa, that I have not thought it desirable to refer it to a different genus, though the name Dendropupa has been proposed by Prof. Owen. Mr. J. S. Jeffreys and other eminent concholo- gists, who have seen the shell, concur in the opinion that it is a true Pupa ; so that this genus, like Lingula and Nautilus, extends from the palaeozoic to the modern times. It may be described as a cylindrical shell, tapering to the apex, with a shining surface, marked with longitudinal rounded ridges. The whorls are eight or nine, rounded, and the width of each whorl is about half the diameter of the shell. The aperture is rather longer than broad ; but is usually somewhat distorted by pressure. The margin of the lip is somewhat regularly rounded and is reflected outward. There are no teeth, but a slight indica- tion of a ridge or ridges on the pillar lip, which may however be accidental. Length fVths of an inch or a little more. It was first recognized by Dr. Gould of Boston, in specimens obtained by Sir C. Lyell and the writer at the Joggins. This little shell is remarkable, not merely for its great antiquity, but also because it is separated by so wide an interval of time from any other known species of its race, there being no other Pulmonate known until we reach the Purbeck beds, and no true land snail until we reach the Tertiary. It is also worthy of remark, that while hundreds of specimens have been found, not only in AIR-BBEATHEBS OF THE COAL PEBIOD. 63 the erect reptiliferous trunks but in a bed 121Y feet lower, and separated by twenty-one coal beds, not any other species is found with it. It is very rare in modern times thus to find one species of snail in great abundance without any others. More especially is this so when we can examine, as in this case, not only the decayed trunks in which the creature sheltered itself, but also the beds of mud into which its dead shells were washed. These facts present a striking instance either of that " imperfection of the geological record", of which we hear so much, or of the solitary existence of a single species as a prophetic representative of future things, to be realized long after it had ceased to exist. The lower bed, holding shells of Pupa vetusta, just mentioned, is a grey and greyish-blue under-clay, full of stigmarian rootlets, though without any coal or erect trees at its surface. It is 7 feet thick, with sandstone above and below. The shells occur very abundantly in a thickness of about two inches. They have been imbedded entire ; but most of them have been crushed and flat- tened by pressure. They occur in all stages of growth ; the young being, as is always the case in such shells, very different in general form from the adults. This bed is evidently a layer of mud deposited in a pond or creek, which afterward became silted up and carried sigillaroid trees. In modern swamps multitudes of shells occur in such places ; and it is remarkable that in this case a single land shell should alone be found, without any trace of aquatic mollusks. The shells which occur in this bed are filled with the surrounding sediment. Those which occur in the erect Sigillarice, on the other hand, except when they are crushed and flattened, are filled with a deposit of brown calc-spar. I infer from this that the latter when buried contained the animals, and consequently that these lived or sheltered themselves in the hollow trees, as is the habit of many modern land snails. The gally-worm of the coal period, Xylobius Sigillarice, must have existed in great numbers, as many layers in the erect treea are full of them. It probably lived in these decaying trunks just as its modern congeners do in similar places. As an air-breathing 64: AIR-BREATHERS OF THE COAL PERIOD. animal, and subsisting on vegetable food, it cannot have lived in water, or even in very wet places ; and this is one of the evidences which in this case point to a greater dryness of the coal swamps than has hitherto been supposed probable ; it also shows the resem- blance of the conditions of the areas of coal accumulation to those of modern forests. With regard to the affinities of XyloUus, its form and structure render certain its alliance with the Myriapods, and with the chilog. nathous division of them, or the gally-worms ; but it is less certain to which of the families of the recent gally-worms it belongs, if to any of them. I have however little doubt that if it existed as a recent animal, it would go into the tribe Bizonia of Newport, and probably into the family of lulidce, to the typical genus of which it bears a strong resemblance in such points as can be made out. The oldest Myriapod previously known is, I believe, the Geophilus proavus, Miinster, of the Jurassic period*. EXPLANATION OF PL. VI, FIGS. 47 TO 53, AND 56 TO 61. Invertebrate Air-Breathers. Fig. 49. Pupa Vetusta, natural size. it so. magnified.