290 CROCODILIANS. 



have crowns which are as round and as thick in proportion to their 

 length as in the recent Crocodiles or Alligators. Some of the teeth 

 of this species are even shorter and more obtuse, as are those figured 

 in PI. 62, A. fig. 9, a and h. The crown is traversed by longitudinal 

 ridges, which are more numerous, more close-set, and more neatly 

 defined than in the Croc, cultridens (Suchosaurus) from the same 

 formation. Two of the ridges, larger and sharper than the rest, 

 traverse opposite sides of the crown ; but are placed as in the Gavial, 

 on the right and left sides, midway between the convex and concave 

 lines of the curve of the tooth. These ridges are confined to the 

 enamel ; the cement-covered cylindrical base of the tooth is smooth. 



The more ancient Crocodiles from the Oolite and Lias, called 

 Steneosauri and Teleosauri had jaws like those of the modern 

 Gavials, but sometimes longer and more attenuated, and armed 

 with more numerous, equal, and slender teeth, adapted for the 

 capture of fishes, which appear to have been the only other ver- 

 tebrate animals existing at those periods in numbers sufficient to 

 yield subsistence to carnivorous Saurians.(l) 



In a specimen of Teleosaurus Chapmanni I have counted one 



hundred and seventy-eight teeth, thus arranged, ^ElS : the Teleo^ 



saurus latifrons had one hundred and forty-two teeth, viz, |£^. 



The Tel Egertoni had gE|. (PI. 75a, fig. 4.) Cuvier calculates 



the number of teeth in the Teleosaurus of the Caen Oolite, which is 



a distinct species from the two above-mentioned, to be one hundred 



and eighty, viz. J|£|\ The enumeration will differ within small limits 



in different individuals of the same species, in consequence of the 



uninterrupted and irregular shedding and replacement of the teeth. 



The foregoing numbers indicate those of the sockets, some of which 



are almost always empty. In the Teleosaurus priscus {Crocodilus prisons, 



Soemmering) the teeth appear to have been shed and renewed in a 



more regular alternate order than in other species. (2) 



In all tlie Teleosauri the teeth are more slender, less com- 

 pressed and sharper pointed than in the Gavial ; they are shghtly 

 recurved, and the enamelled crown is traversed by more numerous 



(1) Buckland's Bridgewater Treatise, i, p. 250. 



(2) Whence the term Aelodon proposed for the species by M. H. v. Meyer. 



