66 



PATAGONIAN EXPEDITIONS: PALEONTOLOGY. 



plete mandible associated with an isolated m-; No. 13 (PI. X, fig. 11), 

 a cast of a fragment of the mandible, also marked "type," but evidently 

 belonging to a much older animal. No. 17 is a cast of the type of P. 

 divortiuni and No. 27 a cast of the type oi P. dichotomum. No. 15,436 

 is a young animal with ma and 3 not yet fully protruded. 





No. 



No. No. 



' 



16. 



17. 14.. 



Upper dentition, 







length i^ - m-S. 



.117 





Upper premolar- 







molar series, 







length 



.087 





Upper premolar 







series, length 



.0465 





Pl, length (z.d'., ant. - 







post, diam.) 



.0095 





Pl, width {i. e., 







greatest transv. 







diam.) 



.0095 





P^, length . 



.010 





" width 



.012 





P-^, length . 



.013 





" width 



.016 





pi-, length . 



•0135 



.013 



" width 



.018 



.018 



Upper molar. 







series, length 



.042 



.041 



Mi, length . 



.015 



.013 



" width . 



.0185 



.018 



M^, length . 



.017 



.015 



" width . 



.021 



.019s 



M-2-, length . 



.014 



.0135 .014 



" width . 



.020 



.0195 .020 



Lower dentition, 







length ij-mg- 







Lower premolar- 







molar series. 







length 







Lower premolar 







series, length 



• 





Pi", length 



. 



.009 



" width 



. 



.004 



Measurements. 



No. 

 13- 



No. 

 27. 



No. 

 15,732. 



No. 

 15436- 



.DISS 



.020 



.112 



.0S9 



.046 



.0085 



.004 



