Bulletin American Museum of Natural History. [Vol. XIXT,. 



metal goods and manufactured wares. In this latter house 

 the storekeeper often finds large accumulations of rice and 

 buckwheat which have been brought by the mice from the 

 other magazine more than three hundred feet away. In 

 the houses they are active during the entire year, and I think 

 young are born in every month, but on the tundra they are 

 inactive during the winter; I caught the most there during 

 August and September, and very few during the summer. 

 In the moist places where the fine grass grows, grass cuttings, 

 and droppings are plentiful, but baited traps set there caught 

 very few of them. I caught several in my cabin with their 

 cheeks filled with rice." N. G. B. 



14. Evotomys jochelsoni, sp. nov. 

 KOLYMA RED-BACKED MOUSE. 



Type, No. 19538, $ ad., Verkhne Kolimsk, Kolyma River, February,. 

 1902; W. Jochelson, Jesup North Pacific Expedition. 



Based on two adult specimens preserved in spirits, collected by Mr. 

 Jochelson as above. Dorsal area, from front of crown to tail, bright 

 rufous, with a slight intermixture of black-tipped hairs, the pelage 

 being dark plumbeous for the basal two thirds, then banded with 

 ochraceous and broadly tipped with rufous; sides ochraceous, in- 

 cluding the front and sides of the head; ventral surface bright buff; 

 tail above dusky, sides and below bright buff, heavily clothed; ears 

 tipped with rusty internally. 



Measurements. Type: Total length, 107 mm.; head and body, 85' 

 tail vertebrae, 22; hind foot, 17. The other specimen has a defective 

 tail (probably due to injury in life), measuring as follows: Head and 

 body, 80; tail, 13; hind foot, 17. Skull, total length, 22; mastoid 

 breadth, n; length of nasals, 6.3. 



This species differs from Evotomys wosnessenskii and . 

 rutilus through the much lighter red of the dorsal area, the 

 strongly ochraceous sides, and the buffy underparts. It is 

 also smaller. It differs so radically in coloration from the 

 Craseomys group (E. rujocanus and E. latastei) that no com- 

 parison with these forms is necessary. 



