Marsh regarded ([404]) the vertebræ as representing a new type of ichthyosaurian ([2]), but there can be no doubt that the vertebræ belong to some form of the Amphibia, since the description applies equally well to them. In this connection mention must be made of a large rib from the Linton beds preserved in the U. S. National Museum. Only the proximal third of the rib is preserved, but it represents some large form of the Stegocephala. The rib is strongly curved backward, is heavy, and has an incipient tubercle. A cross-section shows that a longitudinal groove occupies the median line on the exposed surface of the rib. This may, however, be due to compression and thus indicate that the rib was hollow. The rib as preserved measures: length, 102 mm.; maximum width, 22 mm.; minimum width, 14 mm. (Nos. 4490, 4489, U. S. National Museum.)
Type: Eobaphetes kansensis Moodie.
The new name is proposed to replace the generic term Erpetosaurus used for the species E. kansensis described by the writer (Proc. U. S. Nat. Mus., 39, p. 491, 1911), and which later was found to be preoccupied by Newton (Phil. Trans. Roy. Soc. London, 185, p. 573, 1894 B).
The genus is very readily distinguished by two prominent characters the short, uniform dentition and the presence of two elongate, oval, internal mandibular foramina on the inner side of the jaw. The genus may be further distinguished by the great depth of the posterior portion of the jaw and the slender anterior part, as well as by the ornamentation, which is typically the rough tuberculated labyrinthodont sculpture on the anterior end of the mandible. This changes gradually to longitudinal grooves and ridges of a rather small size on the posterior portion, a very unusual arrangement for a labyrinthodont.
These characters are sustained by those of the skull fragment, in which the dentition is uniform and the sculpture very similar to that of the mandible. The ribs are long, curved, and solid, as in other labyrinthodonts.
The internal surface of the mandible shows much similarity to that of the crocodiles and alligators of the present day. The resemblance is not due to homology of structures, but must be regarded as a parallel development of similar characters.
Eobaphetes kansensis Moodie.
Moodie, Proc. U. S. Nat. Mus., 39, pp. 491-494, figs. 1 to 3, 1911 (Erpetosuchus).