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THE AMERICAN NATURALIST* [Vol. XLIV 



bones into the acetabulum in such a way as to throw the 

 distal end outward, the head of the femur necessarily 

 enters and penetrates the opening of the acetabulum, 

 invading the pelvic cavity and occluding the same. But 

 this is not the worst. The distal end of the femur is left, 

 as Tornier's figures themselves show, protruding into 

 space without any surface whatever with which to artic- 



ulate. I am fully aware that in the lacertilia the joint made 

 by the femur with the tibia and fibula, especially in young 

 individuals, is provided to a high degree with cartilagi- 

 nous connections, and the ends of the bones are covered 



