118 Wortman — Studies of Eocene Mammalia in the 



molar of the lion, which is the first. This fact, however, was 

 impossible of determination from the fragmentary specimens 

 known at the time Professor Marsh's description appeared. 

 The crown is composed of an anterior and posterior cusp, 

 which represent the external and anterior cusps of the trigon, 

 respectively ; of these the posterior is broken away, but it is 

 evident that they were laterally flattened and drawn out upon 

 their edges so as to form a pair of effective blades, as in the 

 sectorial molar of the Felidse. The internal cusp of the trigon 

 has completely disappeared, and the heel is represented by a 

 mere vestigial spur. 



The second specimen of this species was at first referred by 

 Professor Marsh to a distinct species, Limnofelis latidens, 

 together with the lower jaw of the immature individual already 

 considered under the head <di ^Elnr other ium. He subsequently 

 removed it, using the present specimen as the type, to the dis- 

 tinct genus Oreocyon, which he established for its reception. 

 It is now evident, however, that this species is the same as 

 Limnofelis ferox, and the name Oreocyon latidens therefore 

 becomes synonymous with Patriofelisferox. 



Figure 66. — Anterior part of lower jaw of Patriofelis ferox Marsh (type of 

 Oreocyon latidens Marsh) ; side view ; three-fourths natural size. 



The specimen, figure 66, consists of the coossified anterior 

 part of both mandibular rami, carrying both canines, the 

 alveoli, and most of the roots of the incisors, the three pre- 

 molars upon the left side, and the first and second premolars 

 upon the right side. There are, in addition, some fragments 

 of the posterior portions of the jaw, including a condyle, a well- 



