PlcsUtiUurus. 2y 



thickness in proportion to its length, compared with the same 

 part in recent crocodiles, with which circumstance the structure 

 and appearance of the teeth perfectly correspond, being exceed- 

 ingly thick, short, and blunt. Length of one of these teeth, two 

 inches, diameter at base, one inch ; only one-half an inch pro- 

 jecting beyond the alveole. 



We have seen a portion of the jaw of a very distinct species 

 of fossil crocodile, in possession of Dr J. E. Dekay, who is about 

 to describe it in the Annals of the Lyceum of Natural History. 

 This fossil is also from the Atlantic secondary in New Jersey ; 

 it displays considerable analogy with the Crocodllus gangeticus 

 of Cuvier. 



Genus Flesiosaurus, of Conybeare. 

 The fossil vertebrae of a Plesiosaurian reptile, from the New 

 Jersey " marl," is contained in the Cab. of Ac. Nat. Sciences, 

 which we have described in the Journal of the Academy, vol. 

 iv. p. 232, pi. xiv. Although the general character of this ver- 

 tebra associates it with the plesiosaurus, yet the comparative 

 great length of the axis of the bone will distinguish it from any 

 species of that genus hitherto noticed. 



Genus Basilosaurus, Harlar. 



A name we have used to distinguish the remains of an im- 

 mense fossil saurian lately discovered on the banks of the Wa- 

 shita, or " Ouachita,"' river, state of Louisiana, and described 

 in the Trans. Am. Philos. Soc. vol. iv. new series, p. 297, pi. 

 XX. 1834. 



The principal fossil, which forms the subject of this paper, 

 consists of a vertebra of enormous dimensions, possessing cha- 

 racters which enable us to refer it to an extinct genus of the 

 order " Enalio Sauri'' of Conybeare. The animal of which the 

 present remnant constituted a portion existed in a period more 

 recent than that of any of its congeners hitherto discovered. 



On comparison of this vertebra with those of its congeners, 

 it appears to be generically distinct from them all, but bears 

 a closer approximation to the Plesiosaurian vertebrje than to 

 any other. The length of the axis of the bone is twice its di- 

 ameter, being fourteen inches long, and seven inches broad. Its 



