328 THE.PUERCO FAUNA. 



MlOCL^NUS BALDWINI Cope. 



American Naturalist, 1882, p. 853. (October, published Sept. 28.) 

 PI.1t.- XXV f; fig. 16. 



Represented liv a ripht mandibular ramus which supports the last four 

 molars, and contains the alveoli of the second and third premolars as well. 



The specimen shows that the premolars are large, the third the larg- 

 est, and the second and fourth of equal length, and as long as the first true 

 molar. The fourth jiremolar is oval in section and its heel is well devel- 

 oped, and supports a median cusp. The internal posterior cusp of the true 

 molars is well developed. The second true molar has a well-developed ante- 

 rior inner cusp, which is wanting in Hemithlceus opistJiacus. The true molars 

 grow successively narrower posteriorly, so that the last molar is relatively 

 smaller than in H. opisthucus. The ramus becomes shallow anteriorly. It is 

 also compressed throughout. The masseteric fossa is not marked, and the 

 posterior part of the ramus is not incurved. The base of the coronoid pro- 

 cess rises, so as to elevate the heel of the tliird inferior molar. 



Measurements. 



u. 



Length of last six inferior uiolars O-JS 



Length of last four inferior uiolars 022 



Length of P-iu. iv O^'S" 



Length of M. i 0053 



Leugth of M. iii 005.J 



Depth of ramus at M. ii 0100 



De])th of ramus at Pui. ii 006o 



From the Puerco beds; discovered by Mr. D. Baldwin, to whom I have 

 much pleasure in dedicating the species. 



Miocl.«;nus fekox Cope. 



Proceciliugs American Philosophical Society, 1883, p. 54*. 

 Plate XXIV f; fig. et »eq. 



This species is represented by four specimens. One of these includes 

 various separate teeth and a considerable portion of the skeleton; a second 

 includes loose teeth and a smaller number of bones of the skeleton; and the 

 third consists of a part of a mandibular ramus, which contains the three true 

 niolais. Those indicate the largest species of the genus yet known, the first 

 individual above mentioned being about the size of a wolf 



