64 



PATAGONIAN EXPEDITIONS: PALEONTOLOGY. 



P. cingulatum. In all of these cases the reference to P. mtstrale is more 

 or less uncertain, but the available evidence is, in my judgment, insufficient 

 for any separation. 



Upper dentition, length i^-m^ . 

 " premolar-molar series, length 

 " premolar series, length . 

 pi, length (i. e., antero-posterior diameter) 



" width (i. e., greatest transverse diameter) 

 P^, length 



" width 

 P^, length 



" width 

 PA, length 



" width 

 Upper molar series, length 

 Mi, length 



" width 

 M-^, length 



" width 

 M-i, length 



" width 

 Lower dentition, length i^ 



" premolar-molar series, length 

 " premolar series, length 

 Yj, length 



" width 

 Pa, length 



" width 

 P^, length 



" width 

 P5, length 



" width 

 Lower molar series, length 

 My, length 



" width 

 Mg-, length 



" width 

 M3, length . 



" width 



N. B. The discrepancies in the totals are due to overlapping of the teeth. 



Measurements. 







No. 



No. 6. 



No. 21. 



No. 5. 



15,368, 



.109 







.III 



. 





.080 



.072 





.081 



. 





.044 



.038 





.044 



:r) 





.010 



.0085 





.0095 



eter) 





.009 



.008 





.0075 







.0105 



.009 





.010 









.012 



.011 





.0115 









.0105 



.009s 





.0115 









.0145 



.012 





.014 









.013 



.011 





.012 









.0165 



.014 





.0165 









.038 



■034 





.038 









.013 



.010 





.012 









.018 



.017 





.017 









.014 



.012 





•013s 









.020 



.017 





.0185 









.0125 



.0105 





.0125 









.018 



.0165 





.018 









.102 





.104 











.083 





.086 











.044 





.044 











.008 





.0085 











.004 





.004 











.010 





.011 











.006 





.007 











.012 





.013 











.008 





.0095 











.013 



.013 



.012 











.010 



■0103 



.011 











.041 



.040 



.042 











.012 



.0115 



.012 











.010 



.010 



.0105 











.013 



.013 



.013 











.011 



.010 



.011 











.015 



.0145 



.016 











.011 



.0095 



.010 





It will be observed that there is a remarkable difference of size between 



