In 1868 Cope described Palaeophis littoralis, the first fossil snake named from North America. Since then 24 species pertaining to 13 genera have been described by various authorities, although Cope and Marsh were the principal contributors to our knowledge of the extinct Serpentes of this continent.
Such information as has accumulated concerning the extinct snakes of North America is the result of spasmodic and uncorrelated studies, a research that was made difficult by the extreme rarity and the usually fragmentary state of the available specimens. The scarcity of snake remains in the fossil record, aside from their small size, may perhaps be attributed to the fact that with comparatively few exceptions they are terrestrial in habit, and for that reason their skeletons were less apt to be preserved as fossils.
The present study was made possible through the co-operation of the author’s colleagues who upon request, without exception, generously turned over their serpent materials for his use. Thus he was enabled to bring together in the United States National Museum practically all the ophidian specimens known from North America, consisting of all the original types, except Coluber acuminatus (Cope), Ogmophis oregonensis Cope, and Palaeophis littoralis Cope, which appear to be lost, as well as all unstudied material. Of the latter, however, it was disappointing to find so few specimens among the accumulations of many years of explorations.
The very fragmentary character of the original types, consisting at best of a few vertebrae, makes their study very . . .