242 PUERCO FAUNA. 



as the third, and the second, judging from the space and the size of its al- 

 veohis, was much smaller than the third, and the crown was probably a 

 simple acute cone. The crown of the third is of that form, with the addi- 

 tion of a short heel. The long axis of the base of the crown is diagonal to 

 that of the jaw. The fourth premolar has a relatively larger heel than the 

 third, but it is shorter than the diameter of the base of the cusp. Its pos- 

 terior edge is elevated. The cusps of the anterior pair of the true molars 

 are elevated, but the interior is the most so. The supplementary one is 

 not exactly in the line of the interior border of the crown. Each of the 

 inner cusps are connected with the base of the external by a ndge, which 

 together form a V. The posterior base is nearly surrounded by a raised 

 edge, which rises into cusps at the posterior lateral angles. Of these the 

 internal is the more prominent. The edge connecting these cusps is slightly 

 convex backwards, and evidently bears a part in mastication. The lateral 

 borders of the last molar are somewhat expanded, and the fifth lobe is very 

 sliort. No cingula on any of the teeth. 



Measurements. 



M. 



Ivfiigth of dental sorieB from "canine" exclusive 0265 



LeugtU of true molar series 0140 



T^- » „ 11 • II < loiiKltudinal 0040 



Diameters "canine" { ^ 



c trausverse 0030 



Long diameter of base of "Piii. i" ^ 0028 



Long diameter of base of Pm. ii 0017 



0055 



roposterior 0050 



transverse 0038 



anteroposterior 0050 



Length of crown of M. iii 0060 



Depth of raII^ls at Pm. iii 0090 



Depth of ramus at M. iii 0100 



From the Puerco epoch of New Mexico; D. Baldwin. 



MiXODECTES CRASSIUSCULUS Cope. 



Proceed. Amer. Philos. See, 1883, p. 417. 

 Plato XXIVf ; fig. 2. 



This mammal is represented by fragments of three mandibles from differ- 

 ent individuals, one less and the other more worn by mastication. The 

 species differs from the last in its greater size and in the relatively greater 



T\- . T> • ^ vertical 

 Diameters Pm. jv ! 



I anteropi 



Diameters M. ii < 



