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ART. XVII. — Description of a new species of Crocodile from the Miocene of 



Virginia. By Joseph Leidy, M. D. 



Several representatives of the living crocodiles, or such as possess concavo-convex 

 vertebral bodies, have been discovered in the cretaceous strata of the United States. 



Dr. Harlan* characterized a species, to which he gave the name of Crocodilus 

 macrorhynchus, from a fragment of an inferior maxilla having in it eleven alveoli, 

 three of Avhich contained the teeth, found in the Green Sand formation of New Jersey. 



A second species was established by Dr. Morton, f which he designated Crocodilus 

 clavirostris, from an almost entire cranium found in the Cretaceous limestone overlying 

 the marl, near Vincentown, New Jersey. 



Dr. Dekay:!: has described several fragments of an inferior maxilla of a species of 

 Gavial found in the Green-sand formation of the southern part of New Jersey. It is 

 undoubtedly different from the Crocodilus macrorhynchus, Harlan, and also the 

 gavial-like Crocodilus clavirostris, Morton. It may probably belong to one of two 

 species of Crocodilus, since characterised by Mr. Owen,^ of London, from several 

 vertebrae found in the same formation, which of course can only be inferred from 

 relations of size. In the present state of uncertainty whether these fragments of 

 fossil jaw belong to an animal different from any before characterised, it will not be 

 improper to apply to it the name Crocodilus Dekayi, in honor to Dr. Dekay, who has 

 so well described the specimens, because a synonyme, should the species on further 

 discovery prove not to be new, would produce much less inconvenience, than a want 

 of a name at present for convenient reference. 



The two species of Crocodile referred to, characterised by Mr. Owen from some 

 vertebrae found in the Green Sand of New Jersey, were based upon an important 

 difference presented in the form of the inferior spinous process of the posterior 

 cervical and the anterior dorsal vertebrse. In one species the process is double or 

 divided by a median longitudinal cleft; in the other it is single, broad, flattened and 

 smooth below. "Two species, therefore," Mr. Owen observes, "of Crocodile or 

 Allio-ator were thus established." To the first the name of Crocodilus basifissus is 

 applied, and to the other, that of Crocodilus basitruncatus, the two specific names 

 indicating the most striking character of the bones upon which the species were founded. 



♦Journal of the Academy of Natural Sciences, Vol. iv, Pt. 1, p. 15, PI. 1, figs. 1, 2, 8; Medical and Physical 

 Researches, p 369. 

 I Proceedings Acad. Nat. Sci., Vol. ii, p. 82. 



t Annals of the Lyceum of Natural History of New York, Vol. iii. p. 156, PI. 3, figs. 7 — 10. 

 h Quarterly Journal Geological Society of London, Vol. r, p. 380. 



