982 



THE JOHN DAY FAUNA. 



This genus i-epresents a station on the line connecting Binictis with the 

 higher saber-tooths, being intermediate between the foi-mer genus and Hop- 

 loplioneus. It lacks the tubercular inferior molar of Dinictis, and possesses 

 the second inferior premolar characteristic of that genus, which is wanting 

 in Hoplophoneus. One species is certainly known, and a second is provis- 

 ionally referred here. The two are the largest of the saber-tooths of North 

 America, the type, P. plaUjcopis, equaling in dimensions the largest species of 

 Drepanodon, being only exceeded among the tnie saber-tooths by the species 

 of Smilodon. Unfortunately, only the skull of the typical species is known. 

 Several bones of the P. hraclujops have been discovered. 



Fig. 38. — Poyonodon platycopis, less than two-tit'ths natural size. Mus. Copo. 



POGONODON PLATYCOPIS CopC. 



American Naturalist, 1880, ji. 143. Iloplophoneus j'lali/copis, American Naturalist, 1879, p. 798a, Decem- 

 ber. Proceed. Amer. Philo. Soc, 1879, p. 373 (December 24). 



Plate LXXIV a. 



Tlie skull on which this species was established remains a vmique. It 

 is in good preservation, not wanting any important part. The median por- 

 tions of both zygomata are wanting, and the frontal region is crushed and 

 parts of it weathered away. 



The cranium is characterized by the relative elongation anterior to the 

 sagittal crest, the latter being a little more than one-third the length of the 

 skull from its posterior apex to the premaxillary border, and equal the dis- 

 tance from tlie junction of the temporal ridges to the anterior rim of the orbit. 



