93 

 Measu rements. 



M. 



Antero-posterior diameter of ilium -095 



Vertical diameter of ilium -061 



Antero-posterior diameter of acetabulum -029 



Length of centrum of third (?) cervical vertebra (from edge of cup to tip 



of ball) -032 



Height of neural canal, third (?) cervical -0095 



Length of hypapophysis of third cervical -0085 



Length of centrum of a posterior dorsal -040 



Length of diapophysis (about) -032 



Length of centrum of a lumbar -046 



Vertical diameter of a lumbar -029 



Breadth of neurapophysis of a lumbar -027 



CROCODILUS HETERODON, Cope. 



Alligator heterodoti, Proc. American Philosophical Society, 1872, p. 544. 



Represented by a single tooth from the posterior part of 

 the mandibular series. It agrees very closely with the cor- 

 responding tooth of Alligator mississippiensis, but presents 

 some differences. The crown is very low, obtuse, and finely 

 striate ; it is compressed and shows a cutting-edge. Its longest 

 diameter is fore and aft ; both this and the transverse diame- 

 ter are proportionately greater than in the modern species. 

 The constriction of the neck is very decided ; the fang is 

 large, and especially thick. 



Measurements. 



M. 



Fore-and-aft diameter of crown 'O 10 



Transverse diameter of crown '7 



Vertical height of crown 



CROCOUILUS CLAVIS, Cope. 



U. S. Geol. Survey of Terrs. 1872, p. 612. 



This species is indicated by the remains of a crocodilian 

 larger than Crocodilus Elliotii, but very different from it. The 

 pitting of the dermal scutes, and of all the cranial bones, is 

 deeper than in any other of the Bridger crocodilians in our 

 possession, and very strongly resembles that in Alligator 

 mississippiensis. 



The mandible has a long symphysis, and the alveolar 

 border shows the sudden deep depression just behind it, 



