164 Fossil Gavicd from Neiv Jersey^ 



The proportions between the length of the symphysis and 

 the branches of the lower jaw, in the Gavial of Monheim, C. 

 priscus of Sommering, (p. 129) we are unable to compare with 

 our fragment; but the regularly alternating long and short teeth 

 mark sufficiently strong specific differences. In the Gavial of 

 Honjieur the angle of the symphysis is very acute, which sepa- 

 rates it broadly from that of New Jersey ; for this circumstance 

 alone would produce strong difficulties in the shape and confi- 

 guration of the head, and, by consequence, in other parts of the 

 animal. From the Gavial of Caen we can only distinguish our 

 specimen by the relative proportion between the depth and 

 width of the lower jaw. In the Caen Gavial the proportion 

 between the depth and width of the lower jaw, near the sym- 

 physis, appears to be as 1 to 3. 



In the New Jersey Gavial, as 1 to 2. 

 In the living Gavial, as 1 to 5. 

 In the Honfleur Gavial, as 1 to 4. 

 Our specimen is, however, too imperfect to determine this 

 question, which must be left to time and to future observers. 

 Enough, however, has been advanced to establish the existence 

 of remains of gavials in the United States, apparently differing 

 from any others hitherto found in Europe. 



It may not be unworthy of remark, that although Cuvier has 

 only indicated the subdivisions of the group of crocodiles, yet 

 that our fossil clearly indicates a species differing so materially, 

 especially from the alligators and crocodiles proper, as to show 

 the propriety of considering them an independent genus. In 

 effect, the long curved bodies of the teeth, hollow through so 

 great a part of their extent, and terminating at their base in a 

 thin shell of bone, remind one much more of the incisores of 

 the Rodentia, among the mammalia, than of the teeth of a rep- 

 tile. In other respects their similarity to the teeth of saurians 

 is complete ; but, at the same time, sufficiently distinct to war- 

 rant the formation of a well-defined and characterized genus. 

 This portion of a jaw is accompanied with several vertebra, 



