72 MICROTIN^ 



concealed by the longer, stiffer, and peculiarly glossy contour 

 hairs. The eyes are small. The ears, provided with a distinct 

 antitragus, are small, densely haired, and almost completely con- 

 cealed in the fur. The hands are nearly normal and moderately 

 large, with naked palms ; the fingers, including the small thumb, 

 all bear long claws. The feet are relatively large, and are 

 slightly twisted, metatarsal IV forming most of the anterior 

 border of the foot (in its natural position) ; as is common in 



Fig. 45. — Ondatra zibeiJiica Linnseus. 

 Ventral view of skull (enlarged). 



aquatic mammals digit IV tends to be slightly longer than 

 digit III, which is ordinarily the longest toe; all the toes bear 

 claws which are stouter and sometimes longer than those of the 

 fingers ; the soles are naked, with five or four plantar tubercles, 

 of which the postero-internal is very large and elongate; 

 the normal postero-esternal pad is not developed, and the 

 pad which in other voles is usually present between the 

 bases of digits III and IV is sometimes present, sometimes 

 absent. The lateral borders of the foot and of each toe are 

 furnished with conspicuous " swimming-fringes " of stiff hairs, 



