S4 [August, 1844. 



cimen now under consideration, it appears to belong to a Gavial, 

 and in all probability to the G. clavirostris. 



Dr. Harlan, many years ago, described the remains of a fossil 

 crocodile from the lower or ferruginous beds of this series.* These 

 fragments enabled Dr. Harlan to reconstruct the head so far as to 

 identify it as a true crocodile, to which he gave the name of C. 

 macrorhyncus.\ This species is figured in the fourth volume of the 

 Journal of the Academy, and the fossil itself is preserved in the So- 

 ciety's collections. 



During Mr. Lyell's recent visit to this country, he also obtained 

 some fragments of a fossil crocodile which appear to belong to the 

 Procajlian division of this family.:]: 



Prof. Buckland remarks that " as there were scarcely any mam- 

 malia during the secondary periods, whilst the waters were abun- 

 dantly stored with fishes, we might, a priori, expect that if any 

 crocodilean forms had then existed, they would most nearly have 

 resembled the modern Gavial. And we have hitherto found only 

 those genera which have elongated beaks in formations anterior to, 

 and including the chalk; whilst true crocodiles, with a short and 

 broad snout, like that of the cayman and alligator, appear for the 

 first time in strata of the tertiary periods, in which the remains of 

 mammalia abound. §" 



This remark would seem to conflict, in a geological sense, with 

 the observations of Dr. Harlan, as jnst quoted, because his descrip- 

 tion and figure correspond to those of a true crocodile; while the 

 C. clavirostris seems, as we have remarked, to possess an interme- 

 diate organic structure. 



M. Geoffrey St. Hiliare has divided the fossil Gavials into two 

 genera, viz : Teleosaurus and Steneosaurns, which chiefly differ from 

 each other in the position and form of the anterior termination of 

 the nasal canal. As the terminal portion of the snout of the present 

 specimen has not been discovered, we cannot avail ourselves of this 

 generic distinction ; and this uncertainty must continue until the re- 

 covery of the deficient portion may enable us to decide the question. 



* Journal of the Acad. N. S. Vol. IV. 



-j Medical and Physical Researches, p. 309. 



\ Amcr. Journal of Science. Vol. XLVII., p. 214. 



?■ Bridge water Treatise, Vol. I. p. 251. 



