218 THE DESEADO FORMATION OF PATAGONIA 
to place its exact relationships, for the most essential teeth 
are wanting, but it is certainly a distinct genus as indicated 
by the reduced size of premolar 4 and the plump character 
of the teeth. 
Proborhyaena gigantea Ameghino 
P. gigantea Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p. 501. 
We found no specimens of this great carnivor, so I am 
reproducing Ameghino’s figure and measurements. The 
Fig. 144. Right mandible—1/2 natural size, after Ameghino. 
heavy canine is channeled on the sides and much worn on 
the posterior face. Premolar 3 is a plump tooth, its crown 
consisting mostly of a single median cusp, but with a small 
heel behind, and, strikingly enough, premolar 4 is a smaller 
and simpler tooth with a single cusp. 
MEASUREMENTS 
Lower dentition, canine, antero-posterior diameter 30 mm. 
Lower dentition, canine, transverse diameter 20 mm. 
Lower dentition, premolar 1 to molar 3 745 mm. 
Lower dentition, height of mandible under pm. 4 60 mm, 
