PEOSIML^, 245 



Measurements. 



M. 



Length of deutal series, including canine 0240 



Leogtli of premolars 0062 



Length of molars 0114 



Long diameter base canine 0036 



Diameters Pm. iv ^ ''°t«''°P°«*«"'"- ^'^ 



i transverse 0026 



Diameters Pm. M. ii < ''^f«''°P°^*<^""'' 0042 



( transverse 0038 



Depth of ramus at Pm. i 0060 



Depth of ramus at M. iii 0068 



Big Horn bad lands, Northern Wyoming; J. L. Wortman. 

 ANAPTOMORPHUS Cope. 



Proceed. Auier. Philos. Soc, 1872, p. 554. Paleontological Bulletin, No. 8, p. 1. Oct. 12, 1872. llTaahakiits 

 Leidy. Report of the U. S. Geol. Surv. Terrs, i, p. 123, 1873. 



The genus Anaptomorphus was characterized by me in 1872, from a 

 mandibular ramus which exhibited the alveoli of all the teeth, three of them 

 occupied by the teeth, viz, the Pm. iv, and the M. i and M. ii. From the 

 specimen the inferior dental formula was ascertained to be I. 2, C 1, Pm. 

 2, M. 3. The Big Horn collection contains a nearly entire cranium of what 

 is probably a species of the same genus. From it the superior dentition, 

 exclusive of the incisors, is determined to be C 1, Pm. 2, M. 3. The pre- 

 maxillary bones are mostly broken off, but a jjart of the alveolus of the 

 external incisor of one side remains. 



The indications are that the external incisor was a small tooth, not 

 exceeding the canine in size, and it was situated close to the latter. The 

 canine is also small, and its simple crown is not more prominent than those 

 of the premolars. The latter are separated from it by a very short dias- 

 tema. The long diameter of their crowns is transverse to the long axis of 

 the jaw; and each one consists of a larger external and smaller internal 

 cusp. The true molars are also wider than long, and support two exter- 

 nal and onlj^ one internal cusps. 



This genus was founded on the left ramus mandibuli of a single species. 

 The posterior portion is broken away, and the teeth remaining- perfect are 

 the-Pm. 4 and M. 1 and 2. The ramus, though small, is stout, and deeper 



