PLATE 11 
View of left os innominatum, showing the acetabulum; about three-fifths 
natural size. 
Fig. 62. No. 16385, Castor subauratus. 
Fig. 63. No. 43847, Castor canadensis belugae. 
Fig. 64. No. 19229, Castor fiber. 
Note that there is a square angle ventral to the acetabulum in swbauratus and 
fiber, but not in belugae. 
[112] 
