PHARSOPHORUS 



215 



so I have reproduced Ameghino's figure and give his 

 measurements. 



Lower dentition, length incisor I to molar 3 114 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 

 Chubut, west of Puerto 

 Visser, 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. Lef t upper jaw 1/2 natural size; A, 

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



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



SPECIMEN 3192 



Upper dentition, length premolar I to molar 3 

 Upper dentition, premolar 3, length 

 Upper dentition, molar I, length 

 Upper dentition, molar 2, length 

 Upper dentition, molar 3, length 



76 mm. 



10.5 mm., width 6 mm. 



11.5 mm., width 8.5 mm. 



12 mm., width 9 mm. 



.55mm., width 12 mm. 



