18 ANATOMY OF THE WOOD RAT 



Neotoma albigula is of a paler, more buffy color than 

 Homodontomys, and some of the guard hairs, slightly scantier, 

 are buffy instead of blackish. The latter attain a length of 

 onl}^ about 14 mm., while the denser body hairs average 

 about 11 mm. The sides are inclined to be more buffy, with 

 fewer dark hairs, and there is an abrupt line of demarcation 

 between these and the white hairs with plumbeous bases of 

 the ventral surface. There is a narrow zone of hairs along 

 the midventral line which are white to the base, and the 

 pelage of the inguinal and axillary regions, and of the throat 

 and chest, are similar. Especially in males there is often a 

 naked area about 40 mm. long and 5 wide upon the central 

 portion of the midventral line, coarser in texture and more 

 scaly than the remainder of the integument. The hairs upon 

 the dorsmn of the feet are pure white. The tail is rather 

 sharply bicolor, sooty above and white below, and is covered 

 with hairs that are slightly longer than in Homodontomys. 



The coloration of the adult Teonoma is more variable than 

 of the others, varying from a brighter tawny shade to tones 

 of gray. It being an animal of more strictly boreal predi- 

 lections, its pelage, even in summer, is considerably longer. 

 The body hairs are softer than in the other subgenera, and 

 are slightly the longest about the shoulders, where they reach 

 a length of about 22 mm. The long, black, guard hairs, 

 about as numerous as in Homodontomys, may reach a length 

 of 27 mm. There is an abrupt transition of color pattern 

 upon the sides to the white of the ventral surface. The hairs 

 of the lateral portions of the latter are plumbeous at base, 

 but for a width of about 30 mm. along the midventral line 

 they are entirely white. In males the hair of the midventral 

 region of the belly is much coarser over an area about 70 

 mm. long and 35 in width and show a strong buffy discolora- 

 tion. Beneath this the integument is much thickened, 

 forming a glandular area (see p. 16). In females this por- 

 tion of the integument is slightly thickened, but there is no 



