1 54 Bulletin American Museum of Natural History. [Vol. XIX r 



dusky brown, passing posteriorly into the dull yellowish gray-brown 

 of the upper surface of the head; feet dusky grayish brown; claws 

 dusky horn color; ears very small, orbicular, wholly concealed in the 

 fur; tail very short, the upper surface dusky, the lower surface and a 

 long pencil grayish white. Incisors pale yellow. 



Measurements, Total length, 97 mm.; head and body, 78; tail 

 vertebrae, 10; tail to end of pencil, 20; ear from crown, 4; hind foot 

 without claws, 14; with claws, 17; claws of fore foot, 6. 



Skull. Total length, 25; basal length, 22; length of nasals, 6; 

 length of palate, 13.5; zygomatic breadth, 16.5; mastoid breadth, 13; 

 interorbital constriction, 4; upper toothrow, 7. 



The skin belongs to a young adult, which differs from the spirit 

 specimen in being much darker and less ochraceous; dorsal surface 

 dusky brown, almost blackish over the whole middle region of the 

 back, with a very short tipping of pale rusty on some of the hairs, 

 imparting a faint rusty general tint; sides ochraceous ; ventral surface 

 rusty buff, palest on the throat. 



This species differs from Lemmus obensis (Pallas), as de- 

 scribed in great detail by Middendorff (Sibir. Reise, Sauget., 

 pp. 99108, pll. VIII X) from a large series collected on the 

 Taimyr River, in the much richer, brighter orange color of the 

 sides and upper parts, and the orange ochraceous instead of 

 whitish ventral surface. It agrees more closely in coloration 

 with Point Barrow specimens of Lemmus alascensis Merriam, 

 but the under parts are brighter, and it is very much smaller. 

 The two skulls, both quite young, show no distinctive cranial 

 differences. 



This is doubtless the My odes schisticolor Middendorff, but 

 not the M. schisticolor 'of Liljeborg. Middendorff 's specimen 

 was a skin and skull brought by Wosnessenski from Ajan (or 

 Ayan), on the west coast of Okhotsk Sea, about 600 miles 

 south of Gichiga. 



1 8. Ochotona kolymensis, sp. nov. 

 KOLYMA PIKA. 



Type, No. 19535, $ ad., Verkhne Kolimsk, Kolyma River, Yakutsk, 

 Siberia, December, 1901; Waldemar Jochelson, Jesup North Pacific 

 Expedition. 



Based on two specimens in alcohol, collected as above. Pelage very 

 soft and thick. Above pale yellowish brown, strongly varied with 

 black over the median area, less black and more strongly yellowish on 



