2l8 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 I to molar 3 145 mm. 



Lower dentition, height of mandible under pm. 4 60 mm. 



