144 



PROCEEDINGS OF THE NATIONAL MUSEUM 



INTERFEMORAL CROSS-RIBS 

 (NUMBER OF) 



E. MEXICANU5 



SPECIMENS IN sample; 71 



LE-SS THAN 9 RIBS IN 76% 



P^T, AUSTRALIS 

 SPECIMENS IN sample; 26 

 MORE THAN 9 RIBS IN 88% 



6 6 10 12 14 



MAXILLARY TOOTH ROW 

 (LENGTH OF) 



P^ MEXICANUS 



SPECIMENS IN sample: 70 



LESS THAN 4.9MM. IN 86% 



P.T. AUSTRAL IS 



SPECIMENS IN sample: 23 



MORE THAN 4.9MM. IN 91% 



ZYGOMATIC BREADTH 



P^ MEXICANUS 



SPECIMENS IN sample: 65 



LESS THAN 8.5MM. IN 95% 



P. T. AUSTRALIS 



SPECIMENS IN sample; 20 



MORE THAN 8.5 MM. IN 70% 



P Q 

 I I 



GREATEST LENGTH OF SKULL 



P. MEXICANUS 



SPECIMENS IN SAMPLE'. 68 



LESS THAN 15.7 MM. IN 94% 



P. T. AUSTRALIS 



SPECIMENS IN sample: 21 



MORE THAN I6.7MM. IN 99% 



Figure 16. — Comparison of frequency of occurrence of certain measurements in adult 

 female P. mexicanus (solid symbols) and P. t. australis (open symbols), including all 

 measurable individuals studied. 



