CHAPTER IV 

 EXTERNAL FEATURES 



Measurements and weights 



Neotoma is a rodent of rat-like form and size; but there is 

 much variation within the genus as regards the latter char- 

 acter. Body length varies from 150 mm. in the case of 

 Neotoma lepida, to as much as 238 in some races of Teonoma, 

 although selected males of Homodontomys (as fuscipes) 

 having longer tails seem to surpass all other wood rats in 

 total length. 



Neotoma (Neotoma) alhigula albigula. Averages of the 

 collector's measurements in millimeters for a series of fifteen 

 adult topotypes secured by the writer and now in the col- 

 lection of D. R. Dickey, are as follows: For eight males: 

 length of head and body, 194 (169-209) ; tail, 144 (125-165); 

 hind foot, 33.6 (32-37). For seven females: length of head 

 and body, 186 (167-203); tail 144 (123-153); hind foot, 

 33.7 (33-34). A specimen typical of those used for dis- 

 section weighed in the flesh 182 grams, while after it had 

 been preserved in spirits and allowed to drain for five min- 

 utes, its weight was 235 grams. Hence, this specimen had 

 soaked up moisture to the extent of nearly 30 per cent of its 

 original weight. The others may be presumed to have 

 done the same in like proportion. 



Neotoma (Homodontomys) fuscipes macrotis. Averages of 

 the collectors' measurements for a series of sixteen adult 

 topotypes in the collection of the Biological Survey are as 

 follows. For eight males: length of head and body, 190.6 

 (170-209); tail, 177 (170-195); hind foot, 38 (35-40). For 

 eight females: length of head and body, 183 (160-200); 

 tail, 170 (160-175); hind foot, 37.4 (35-38). A spirit 



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