Cope.] 468 ^Oct. 20, 



Conoryctes crassiouspis Cope, 



The posterior part of a mandibular ramus supporting the last two molar 

 teeth indicates a second and larger species of the genus. The ramus is 

 one-half deeper than that of the G. comma, and the second true molar is 

 much larger than in that species. The last true molar is much smaller 

 than*the the penultimate, and consists of three anterior cusps and a longer 

 heel. The former are obtuse, the external the longer, the internal equal, 

 the anterior on the inner edge of the crown. The heel sustains a low 

 conic tubercle. 



From the Puerco beds of N. W. New Mexico. 



Phenacodontidse. 



Protogonia plidfera Cope, Amer. Nat. 1883, Oct. (Sept.), p. 833. 



Protogonia subquadrata Cope, Proceedings Amer. Philos. Soc. 1881, p. 492 



Phenacodus puereemis Cope, Proc. Amer. Philos. Soc. 1881, p. 493. 



Phenacodus zuniensis Cope, loc. cit. p. 493 ; loc. cit. 1881 (18.82), p. 180. 



Pantolamhda bathmodon Cope, Amer. Nat. 1883, p. 418. 



Mioclcenus turgidus Cope, Amer. Nat. 1881, p. 830. 



Mioclmnus minimus, sp. nov. 



This is one of the least mammalia of the Puerco fauna, exceeding by a 

 little the Hyopsodus acolytus. It is represented by parts of two mandibles, 

 which display all the true molars. As there are no premolars preserved, 

 its reference to the genus MiodcBnus is provisional only, but its true molars 

 have the peculiar characteristics of those of the M. turgidus. 



The two anterior cusps of the true i^olars are higher than the heel, and 

 they are united together to a point above the level of the heel. The sec- 

 tion of both those of the M. ii is round ; that of the external one of the first 

 is cresentic ; of the inner cusp, round. The heel is wide, and supports a 

 cusp at the posterior external angle. It is bounded posteriorly, and on the 

 inner side by a raised ridge, which gives with the cusp, on wearing a 

 comma-shaped surface. A transverse ridge closely appressed to the ante- 

 rior cusps connects them anteriorly. In one of the specimens there is a 

 cingulum on the external side of the second inferior molar ; on the other 

 specimen it is wanting. Enamel smooth. 



The mandibular ramus is rather deep and compressed, and displays an 

 external ridge on the anterior border of the corouoid, which is not con- 

 tinued downwards. 



Measurements (J^o. 2). M. 



Length of basis of true molars 0125 



Diameters M. « | anteroposterior 0040 



t. transverse 0035 



Depth of ramus at M. ii '. 0073 



From the Puerco beds of New Mexico. D. Baldwin. 



Mioclamus suUrigonus Cope, Amer. Nat. 1881, p. 490, 491 . 



Mioclcenus protogonioides Cope, loc. cit. 1883, Oct. (Sept.), p. 833. 



Mioclcenus mandibularis Cope, Amer. Nat. 1881, p. 830. 



Mioclcenus baldwini Cope, loc. cit. 1883, Oct. p. 833. 



