312 PROCEEDINGS OF THE ACADEMY OF [1892. 



and morphologically. The advance sheets of Osborn and Wortman's 

 paper enable me to give a brief account of it here. The dental 

 formula is If Cx PI M|. The superior premolars increase regu- 

 larly in size from before backward. f\ is small, simple and one- 

 rooted ; P2 is also small and has an incipient deuterocone, repre- 

 sented by an elevated and crenulate internal cingulum ; on Pa ^"d ^ 

 the deuterocone is distinct and supported on a separate fang ; p* has 

 three external cusps, a high protocone, a smaller tritocone which 

 forms a trenchant heel, and a small protostyle ; the tooth thus has 

 all the elements of the feline sectorial, ^i is large and strictly tri- 

 gonodont ; the cusps are all very high and acute, the para- and 

 metacones show no tendency to coalesce and there is no posterior 

 trenchant crest given off from the metacone. ^2 is very small, a 

 mere oval rudiment, with no distinguishable elements. The ante- 

 rior lower premolars all have a compressed, pointed and trenchant 

 protoconid and a small posterior basal cusp, and p^ has an anterior 

 cusp in addition. In the molars the proto- and paraconids are flat- 

 tened, brought into nearly the same antero-posterior line and form 

 an efficient shearing blade, but retaining a well developed meta- 

 conid ; the talon is small and basin-shaped and on m^ very much 

 reduced. 



The cranium is long and the face much shortened ; the orbits are 

 large and situated far forward ; the anterior nares are very large 

 and the muzzle abruptly truncated. The mandible has a short, 

 deep and massive horizontal ramus and a very broad ascending 

 ramus, which terminates in a blunt coronoid ; the chin is abruptly 

 rounded and the symphysis short. The physiognomy of this skull 

 is strikingly feline in character. 



One American species : P. occidentalis Osborn : Wasatch. 



AMBLOCTONUSi Cope. 



The only known specimens of this genus are so much mutilated 

 that an accurate account of it cannot be given. According to 

 Osborn^ the dental formula is P| ML The external upper incisor 

 is much enlarged and the canines are of great size. ^ is triangular 

 in shape, with veiy large deuterocone, a trenchant tritocone and a 

 small protostyle. ^ differs from that of Palceonictis in the reduction 



1 Syst. Cat. Vert. Eocene of New Mexico, U. S. Geog. Surv. W. of 100th 

 Mer., 1875, p. 7. 

 ^ Loc. cit. 



