On teeth of the latter kind Emmons established his Palaeosaurus carolinensis and P. sulcatus; and Leidy, Compsosaurus priseus and Eurydorus serridens. On teeth of the former kind Emmons based his Clepsysaurus pennsylvanicus in part; his Rhytidodon carolinensis and R. sulcatus; Leidy's Omosaurus perplexus and Lea’s Centenodon sulcatus had a similar origin. The names based on the lenticular teeth accompany, as prior to, or synonymes of the latter series. There is much difficulty in collating them, but I may follow Emmons at present, in seeing in the two styles of smooth and fluted teeth, those representing different species.
In this way I have attached to the fluted toothed Rhytidodon carolinensis, Emmons, the Palaeosaurus sulcatus of the same author. Emmons does not offer any grounds of separation for his R. sulcatus, nor Lea his Centenodon sulcatus; neither can I find aught in Leidy's Omosaurus perplexus by which it can be separated. Leidy represents it to be an “Enaliosaurian,” while Emmons says (North American Geology, 67–79–82), that it is the same as his Clepsysaurus and Rhytidodon, citing Leidy as authority for this close approximation. If this be the case, the form is a shore-loving Belodont, and not nearly related to the marine reptiles included under the old name of Enaliosauria.
To the smooth toothed type belong posterior teeth named by Emmons, Palaeosaurus carolinensis, and by Leidy, Compsosaurus priseus and Eurydorus serridens, and anterior teeth referred, erroneously in part, as I believe, to Clepsysaurus pennsylvanicus, Lea. The first mentioned name cannot be used, as it has been already applied to a member of this genus. The third was based on a specimen from a very remote locality, and its proper application remains uncertain. The second specific name may be employed in the uncertainty, though its describer included both fluted and smooth teeth in the same species.
Specimens in the Academy Mus., from Montgomery Co., N. Ca., consist of vertebrae, tarsal bones, etc., and parts of cranium with dermal bones of this species. A tooth in place in the extremity of the ramus of the mandible, is as smooth as those from more posterior positions in the jaw, figured by Emmons, N. Am. Geol., p. 69, fig. 42, which in some measure supports Emmons' hypothesis of the uniformity of the characters of the surface sculpture. The cranial fragments indicate a Belodont, and the vertebrae are different from those of Clepsysaurus.
The vertebrae, (No. 5) from the coal of Chatham Co., N. Ca., were accompanied by teeth of the fluted character, though they were not on the same block. As the former indicate a species distinct from that from Montgomery Co., I have regarded them as probably pertaining to Emmons' Rhytidodon carolinensis.
The remains, (No. 6) from Phoenixville, include vertebrae, bones of the pelvic arch and posterior limb, with dermal bones, but no teeth. They indicate an animal distinct from
either of the preceding.
