1916] HolUger: Anatomical Adapt atio7is in the Pocket Gopher 457 



ally much heavier than that of the tree squirrel. In the rabbits the 

 humerus is smooth and round, with a very large head for articula- 

 tion with the glenoid cavity of the scapula. The deltoid tuberosity 

 is hardly noticeable in the rabbits. The humerus is relatively 

 heaviest among the rabbits in the Belgian hare. 



The ulna {ill., figs. H, I) in the gopher is flattened laterally in 

 its proximal three-fourths and rounded in its distal fourth. The 



_ olec. 



olec. 



- sent. no. 

 end. proc. 



nk. 



I — St. proc. 



-St. proc. 



J 



Fig. H. Lateral view of right ulna and radius of the gopher, X 2| 



Fig. I. Posterior view of right ulna of the gopher, X ^i 



Fig. J. Anterior view of right radius of the gopher, X ^i 



die. tub. — bicipital tuberosity rad. — radius 



cncL. proc. — coronoid process sem. no. — semilunar notch 



lat. gv. — lateral groove st. proc. — styloid process 



nk. — neck ^ll. — ulna 



o lee. — olecranon 



sigmoid notch occupies the cephalic surface one-fourth the length 

 of the bone from its proximal extremity ; it is bounded by the lip 

 of the olecranon process proximally and by the coronoid process 

 distally. These processes are broad, and higher mesially than 

 laterally. The olecranon process is very long and heavy, and a 

 sharp projection at the mesial side of its tip (fig. I) greatly 

 increases the surface for muscular attachment. The lateral surface 



