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On the Remains of a Reptile (Dendrerpeton Acadianum, Wyman and Owen) and of a Land Shell Discovered in the Interior of an Erect

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On the Remains of a Reptile (Dendrerpeton Acadianum, Wyman and Owen) and of a Land Shell Discovered in the Interior of an Erect 58 PROCEEDINGSOF THE GEOLOGICAL SOCIETY. [Jail. 19, JANUARY 19, 1853. John Brogden, Jun., Esq., was elected a Fellow. The following communications were read :-- 1. On the REMAINS Of a REPTILE (DENDRERPETON ACADIANUM, tVyman and Owen) and of a LANV SHELL discovered in the INTERIOR of an ERECT FOSSIL TREE in the COAL MEASURES of Nova SCOTIA. By Sir CHARLES LYELL, F.R.S., V.P.G.S. &c., and J. W. DAWSON, Esq. [Plates II., III., IV.] DESCRIPTIONS and sections of the Coal-formation of Nova Scotia, and particularly of the cliffs called the South Joggins, have been pub- lished by Messrs. Jackson and Alger*, Mr. Brownt, Dr. Gesner~, Sir C. Lyellw and Mr. Logan]l. In September last (1852) the authors of the present notice re-visited and re-examined the strata in a part of these cliffs, with a view of ascertaining what may have been the particular circumstances which favoured the preservation of so many fossil trees, at so many different levels, in an erect position; such a position being a rare ahd very exceptional fact in the coal strata of North America generally. We were also desirous of ob- taining additional evidence on a point which is still a matter of con- troversy in the United States and elsewhere (although we ourselves were already satisfied with the evidence adduced by Mr. Binney82and others), namely, the relation of Stigmaria, as a root, to 8igillaria. We also directed our special attention to the difference of the depo- sits enveloping the upright trees, and those which fill the trunks themselves, forming casts within a cylinder of bark now turned to coal, the central wood of the trunk having decayed. We searched diligently for fossils in these stony casts, suspecting that organic bodies preserved in so peculiar a situation might differ from such as are buried in ordinary subaqueous strata. With this object we em- ployed a labourer to dig out many vertical trees from the cliffs, so that we might break them up and carefully examine their stony con- tents. To clear out the trees, so as to expose to view both their trunks and roots, is a work of no small bodily labour. We reserve for a future communication to the Society an account of the general results which we obtained from an inspection of a series of coal-measures 1400 feet in thickness, and shall confine our present remarks to a few strata, not more than 10 feet thick, which enclose certain vertical trees ;---one of these trees having Stigmarian roots, See Jackson and Alger on the Mimn~logy and Geology of Nova Scotia, SilL Amer. Journ. xiv. p. 305, 1828, and Mere. of Amer. Acad. of Arts and Sciences, voL i. New Ser. 1833. Cambri~e, Mass. t Reports on Nova Scotia Coal Fields, 1829. Remarks on the Geology and Mineralogy d Nova Scotia, 1836. w Travels in North America, 1845, vol. ii. p. 180. II First Report of Survey of Canada, Appendix, 1845. 82See E. W. Binney, on the Dukinfield and St. Helen's $/9///a~, Quart. Journ. Geol. Soc. vol. ii. p. 592. 1846. t853.] LYELL AND DA'WSONmREPTILE AND LAND SHELL. 59 and another containing in its interior.the first examples yet known in America of Reptilian bones, together with what we believe to be a Land Shell, of which last also no instance seems to have been pre- viously observed in rocks of the Carboniferous ~era. After we had already, in the course of this investigation, met with fragments of Plants, such as Ferns, Poacites ?, Nceggerathia?, Sigillaria, Stigmaria, and Calamite in the inside of several trees, we at length found near the base of an upright trunk some dermal plates, together with bones, one of which we conjectured to be the femur of a Reptile, feeling sure at least that it differed from any Fish bones with which we were acquainted. This led us to return next day to examine the same trunk more thoroughly. We accordingly broke up the remaining portion, and found what we imagined might possibly be the jaws and teeth of a Zabyrinthodon, which we supposed to belong to the same individual as the bones. These osseous remains were scattered about in the interior of the trunk among fragments of wood converted into charcoal, as if they had accumulated while the tree was rotting away. All the fragments were cemented together by a dark-coloured cal- careo-argillaceons and sandy matrix. From their position in the tree, we concluded, or rather guessed, the fossil relics to be those of an air- breather, but pretending to no sufficient osteological knowledge to determine a point of such importance, we lost no time in submitting the collection to Professor Jeffries Wyman, of Harvard University, at Boston, who soon declared his opinion that the bones of the extre- mities resembled those of the Batrachian Reptile called Menobran- chuB, which now inhabits the Ohio river and Lake Champlain. In regard to its dimensions, he estimated this fossil ichthyoid quadruped to have been between 2 and 3 feet in length. In breaking up the fragments of rock, Professor Wyman detected in the same matrix a series of nine small vertebrae, two of them having what appeared to be short ribs connected with them (like those of a Salamander). These vertebree he believes to be dorsal or lumbar, and to have belonged to an adult individual of a different and much smaller species of reptile, not exceeding 6 inches in length, whereas the Dendrer2eton dcadia- hum was probably 2~2 feet long. Professor Wyman, feeling considerable diffidence as to his deter- mination, in consequence of his limited means of osteological compa- rison, requested one of the authors to show his notes, together with the specimens, to Prof. Owen, before they were laid before the Geo- logical Society. To this proposal Prof. Owen has promptly and kindly acceded, fully confirming the principal conclusion to which the American anatomist had arrived, namely, that the characters of the fossils are those of Perennibranchiate Batrachians. The Hun- terian Professor has also, in compliance with a suggestion of Dr. Wyman, added notes of his own on several points where he differed somewhat in opinion as to anatomical details. Prof. Quekett, of the College of Surgeons, has had the kindness to examine microscopi- cally longitudinal and transverse sections of one of the larger bones ; and he states that it exhibits very decidedly Batrachian structure, and that the bone-cells (P1. III. fig. 8) closely resemble those seen 60 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Jan. 19, in Menopoma and Menobranchu~* (fig. 10). Prof. Quekett has also found similar batrachian structure in the small vertebrve above alluded to. (See P1. III. fig. 9.) In breaking up the rock in which the reptilian remains were im- bedded, Dr. Wyman found another fossil body, which he and Sir C. Lyell immediately suspected to be a Land-Shell allied to Pupa or Clausilia, having the central whorls larger than the anterior and pos- terior ones, and exhibiting the same kind of striation as characterizes the shells of these pulmoniferous mollusks. Dr. Gould, of Boston, detached the same fossil more completely from the matrix (see P1. IV. figs. 1, 2, 3, 4) ; but he was unable to discover the month, so as to enable a conchologist to determine the genus with precision. He ob- served that in its form and striation it bore no resemblance to any known marine shell. M. Deshayes, when the fossil was shown to him, declared at once his opinion that it was the shell of a pulmoni- ferous and terrestrial mollusk, of the same family as that to which Helix and Pupa belong. [Doubts, however, having been expressed by other pala~ontologists (since this paper was read) as to the correctness of this conclusion, the specimen was submitted to Prof. Quekett for microscopical exa- mination. Part of the striated or finely grooved surface, on being magnified 50 diameters (see Pl. IV. fig. 5), presented exactly the same appearance as a portion, corresponding in size, of the surface of the common English Pupajuniperi (see P1. IV. fig. 6). On making sections of such parts of the fossil shell as were not in too crystalline a condition to exhibit structure, Prof. Quekett detected the same prismatic or hexagonal tissue and the same tubular structure as are generally characteristic of the shells of molluscs, and as may be seen in the recent Pupa, P. juniperi, before alluded to. See PI. IV. figs. 7-14. One of the sections, moreover, exhibited what may pro- bably have been a portion of the eolumella and spire somewhat crushed (P1. IV. fig. 7, upper part), for, as will be seen by the magnified representation of the entire shell (P1. IV. figs. 2--4), it had been subjected to considerable pressure, and had been slightly flat- tened and fractured.--March 21, 1853.] More than usual hesitation has been felt in acceding to the con- clusion that this fossil belonged to the family Helieida~, inasmuch as no land-shell had previously been observed in an.y palseozoic rock; but the mode of occurrence of this body appears m perfect accord- ance with the idea of its being referable to a pulmonfferous mollusk, since it was lying among the rotten wood in the interior of a hollow tree, the upper part of which doubtlessly projected into the air 8 or 9 feet above the roots, or into the water during river inundations. In connexion with the reptilian remains, it may not be irrelevant to observe, that Mr. Logan and Dr. Harding have previously called attention to the foot-prints of a quadruped imprinted on sandy slabs, 9In a plate of the volume of the HistologicalCatalogue, Mus.
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