PHARSOPHORUS 



215 



so I have reproduced Ameghino's figure and give his 

 measurements. 



Lower dentition, length incisor 1 to molar 3 1 14 mm. 



Lower dentition, length premolar I to molar 3 90 mm. 



Lower dentition, height of mandible under pm. 4 38 mm. 



Pharsophorus tenax Ameghino 



P. tenax Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p. 504. 



The species was based on a fourth premolar which was 

 10 mm. long as compared with 13 mm. in P. lacerans. We 

 found on the Chico del «•»* mi 



Chubut, west of Puerto 33 fiL*4 

 Yisser, both an upper and 

 lower jaw belonging to this 

 species, which give us the 

 knowledge of the upper den- 

 tition for the genus. The 

 species is distinguished by 

 the smaller size, relatively 

 heavy jaws, and plump 

 teeth, indicating a heavier built animal than P. lacerans. 

 The following measurements distinguish the species. 



Fig. 140. Left upper jaw — 1/2 natural size; A. 

 molars 3 and 4 from above; B, molars from ex- 

 ternal side. 



Fig. 141. Right mandible — 1/2 natural size. 



Specimen 3192 

 Upper dentition, length premolar 1 to molar 3 

 Upper dentition, premolar 3, length 

 Upper dentition, molar 1, length 

 Upper dentition, molar 2, length 

 Upper dentition, molar 3, length 



76 mm. 



10.5 mm., width 6 mm. 



1 1. 5 mm., width 8.5 mm. 



12 mm., width 9 mm. 



55mm., width 12 mm. 



