104 STUDIES IN TASMANIAN MAMMALS, LIVING AND EXTINCT, 



TIBIA. 



The tibia of N. mitchelli is generically similar to that 

 of the second group, but shows various departures from 

 that type. The shaft upon the whole (allowing for age 

 characters) is similar, but the articular surfaces show the 

 variations we might expect to find in animals whose gait 

 was dissimilar. 



COMPARATIVE SIZES OF TIBIAE, IN THE TWO 

 GROUPS. 



THE FIBULA. 



If anything, the fibula of X. mitchelli is more bent in 

 the shaft than that of the second group, and the articu- 

 lar surfaces manifest their own special characters. These 

 need not be noted in extenso, as the size of the bone will 

 serve to separate it from one of the other race. 



COMPARATIVE FIBULA. 

 (No. 1 = X. mitchelli. No. 2 = N. tasmanicum.) 

 mm. No. 2. n 



Total length be- 

 tween two verti- 



No. 1. mm. 



Total length be- 

 tween two verti- 

 cal plates = 282 



Greatest proximal 



width = 84 



Least proximal 



width = 67 



Greatest distal 



width = 59 



Least distal width — 49 



cal plates = 248 



Greatest proximal 



width ..'" = 73 



Least proximal 



width = 64 



Greatest distal 



width = 52 



Least distal width = 43 



