OF THE CLASS MAMMALIA. 



249 



the bones of the haunches (i) articulate in an immovable 

 manner with the sacrum (sa), and reuniting inferiorly, form 

 a girdle or pelvis, thus surrounding the lower portion of the 

 trunk. The form and dimensions of this girdle vary much, 



Fig. 214. The Mole. 



and ccs fen's paribus, the erect position on the lower limb is 

 easier as the pelvis is larger. It must also be remarked, that 

 in the opossums and other marsupial animals, the muscles of 

 the abdomen assisting in the formation of the pouch of these 

 animals, are attached to two peculiar bones articulated to the 

 anterior parts of the pelvis, and called by anatomists the 

 marsupial bones* (Fig. 212 m). 



Humerus of the 

 Mole. 



Anterior Limb and Hand of the Mole. 

 Fig. 215. 



In the arm and thigh in all mammals there is but one 

 bone, the humerus and the femur; in the fore-arm and leg, 

 two bones the radius and ulna in the fore-arm, the tibia and 

 perone or fibula in the leg. In bats there is a rotula in the 



* These bones are present whether the pouch be there or not. R. K. 



