SCOTT : LITOPTERNA OF THE SANTA CRUZ BEDS. 



79 



facial region of a skull, with all of the upper teeth intact and in a moder- 

 ately advanced state of wear, the hinder portions of the left ramus man- 

 dibuli, with the molars in place, and several limb- and foot-bones in a more 

 or less incomplete condition, as figured in PI. XI. The relatively large 

 size of the tusks and the prominent cingulum of the grinding teeth, exter- 

 nal in the upper teeth and internal in the lower, probably indicate that the 

 animal was a male. 



The upper dentition, so far as can be judged in its worn condition, does 

 not differ in any important way from that of P. australe. P- is quite 

 simple and has a low internal cingulum ; p- and - have a large, well-devel- 

 oped postero-internal cusp (tetartocone), which gives the crown, especially 

 of p-, a subquadrate outline. M- has a much reduced postero-external 

 cusp (metacone) and the hypocone, which in P. australe is wanting, is 

 small, but quite distinct. It is in the lower molars that the most distinctive 

 features appear and, had these teeth alone been found, one would have 

 had little hesitation in referring them to Licaphrium. As in that genus, 

 the valleys are shallow, the crescents thick and massive, and the pillar in 

 the posterior crescent is much larger and more conspicuous than in any 

 of the foregoing species of Proterotherium. 



Upper dentition, length i^-m-2. 



I^, antero-posterior diameter . . .0075 



" transverse diameter . . . .007 

 Upper premolar-molar series, length .079 

 " premolar series length . . .044 



Pl, length (i. e., antero-post. diam.) .0095 



" width (i. e., greatest trans, diam.) .007 

 P^, length .0105 



" width 01 1 



P^, length 012 



" width 01 35 



P^, length 013 



" width 016 



Upper molar series, length . . -037 



Measurements 

 108 



Ml, length 013 



" width . . . . . .017 



M-^, length . . . . . .014 



" width 0185 



M^, length . . . . . .012 



" width 018 



Lower molar series, length . . .0415 

 Mj-, length oi2 



" width ..... .oio 



M2, length . . . . " . .013 



" width on 



M^, length 016 



" width 010 



Most of the bones are in such a broken and crushed condition that accu- 

 rate measurements are very difficult or quite impracticable. The dimen- 

 sions in the following table are, however, close approximations to the 

 truth. 



