38 * PATAGONIAN EXPEDITIONS: PALEONTOLOGY. 



No 83. No 85. 

 pi-, length 018 



" width 023 



Upper molar series, length ......... .056 



Mi, length . 0205 .0205 



" width 025 .025 



M^, length 022 



" width 028 



M-^, length . .017 .018 



" width .025 .024 



Lower dentition, length . . . . . . . . . . .140 



" tusk, greater diameter ......... .0095 



" " lesser diameter ......... -0075 



" premolar-molar series, length . . . . . . . .124 



" premolar series, length ........ .063 



Pg, length 015 



" width 008 



Pg, length 0185 



" width 012 



P4, length 018 



" width 014 



Lower molar series, length . . . . . . . , . .061 



My, length 018 



" width 014 



Mg-, length 021 



" width . . 013 



M-J-, length .020 



" width . .011 



Localities. — Not given for type oi D. robustus or for that oiD. ccelops. 

 DiADiAPHORUS VELOX Ameghino. 



(Plates II, Figs. 3, 4 ; III, Fig. 8.) 



Diadiaphorus velox Amegh.; Enum. sistematica, etc., 1887, p. 20. 



Of this, the smallest known species of Diadiaphorus, I have seen no 

 upper teeth. According to Lydekker ('93, p. 60), "the upper molars are 

 somewhat smaller than those of D. majuscuhis and of much more brachyo- 

 dont type, the valleys being shallower and more open and the columns 

 lower." Lydekker's figures {op. cit., PI. XXV, figs. 7, 8) show that in this 

 species the upper grinding teeth are broader transversely in proportion to 

 their antero-posterior length than in the preceding species. Further, this 

 author says that "the associated lower molars show a small tubercle in 



