152 THE WASATCH AND BlUDGER FAUN^. 



unknown. I distinguish the species described in the succeeding pages by 

 the following characters, among others : 



Teeth with coarse sulci at the base only ; crowns long C. subulatus. 



Teeth with liner deep sulci extending towards the apex of the robust 



crown C. sulci/erus. 



Teeth acute, compressed; crowns with numerous shallow sulci; muzzle 



slender ; no distinct ledge or smooth space on frontal hone G. acer. 



Teeth without sulci, crowns robust; frontal bone with a transverse ledge, 



with a smooth space in front of it ; premaxillaries conical C. affinis. 



Teeth without sulci; frontal without ledge, honeycombed; premaxillary 



teeth conical C. clavis. 



Teeth without sulci; front plane, honeycombed; premaxillary teeth com- 

 pressed, trenchant ; size small C. heterodon. 



Crowns of teeth unknown ; sizes very irregular, numerous small teeth 



with a few large ones interspersed .... G. polyodon. 



The C. affinis and C. elliottii belong to the section oi* genus Thecachampsa 

 Cope, which is characterized by the concentric structure of the teeth They 

 are composed of layers, which fonn a cone-in-cone structure, each cone 

 being distinct from the one which it incloses. I do not know the structure 

 in the other species above named. 



I have formerly referred two of the species, the C. subulatus and G. 

 polyodon, to Diplocynodus Pom, a genus characterized by the presence of 

 two similar and adjacent canine teeth in the ramus of the mandible. C. 

 subulatus has two such canines in the upper jaw, but there is no eNidence 

 that there are such present in the lower, as the mandible is broken off an- 

 terior to the canine which is present. 



The typical specimen of C. liolyodon is broken in the same manner, so 

 that I leave it also provisionally in Crocodilus. 



Crocodilus subulatus Cope. 



CrocodUuK (Ichlhi/osuchwi) mihulatuii Cope, I'rocecMl. Anier. Pliilos. Si>o., 1872, j). .''>r>4 (October 12). Diplo- 

 cynodm suhulatiii Copi', Annual Kriiort U. S. Geol. Surv. T«>rre., F. V. Hayilen iu ch.'irgf, ls72 

 (1873), p. 6i:t. 



Plato XXIV, figs. 5-19. 



Some of the cervical vertebrae without hypapophyses. Their cups 

 round, with smooth bordering surface of the sides of the centrum. The 

 jaws only are preserved from the cranium ; the premaxillary is strongly 



