ASCHIZOMYS 279 



Renmrls.—So far as our present knowledge goes Aschizomys, 

 represented by a single specimen, the type of A. leimainus, " is 

 apparently a most remarkable descendant from some old species 

 of Evotomys. In skull and in the pattern and lightness of the 

 cheek-teeth it is practically identical with Evotomys. But 

 living in the high north, it has acquired the outward form of a 

 lemming; and subsisting apparently upon a diet which rapidly 

 wears away the crowns of the cheek-teeth, the latter have 

 become hypsodont and rootless as in the higher voles." Since 

 I wrote the passage just quoted my studies have shown that 

 " Phaulomys " and '" Caryomys," reputed generic groups with 

 cranial and dental characters exactly like those of Aschizomys, 

 are based upon immature individuals of E. rufocaiius, and 

 I now suspect that Aschizomys leiiiminus will prove to be a 

 member of the E. rufocanus group, although sharply distinguished 

 as a species from E. mfocanus by its external peculiarities. 

 It is to be hoped that further material will be forthcoming 

 from the neighbourhood of Plover Bay. 



1. Aschizomys lemminus Miller. 



1898. Aschizomys lemminus Miller, Proc. Acad. Nat. Sci., Phila- 

 delphia, 1898, p. 369. 



Type.—V.a. Nat. Mus. No. .ffWW ; "adult" in alcohol, 

 collected by C. W. Baxter. 



Type locality. — Kelsey Station, Plover Bay, Bchring Strait, 

 N.E. Siberia. 



Range. — Known only from the type locality. 



Characters. — Size medium. Bars broad and rounded, longer 

 than fur immediately in front of their bases. Hands large, palms 

 naked, with five prominent tubercles; claws short and stout; 

 thumb vestigial with a convex compressed nail. Feet broad ; soles 

 with six pads, of which five are subequal and one much smaller, 

 posteriorly densely haired between heel and hindermost tubercle, 

 anteriorly granular and clothed with a considerable number of 

 short white hairs interspersed among the granules; claws 

 moderately developed, overhung with white hairs. Tail club- 

 shaped. Whiskers long, reaching to shoulders. 



Fur dense, soft and silky, about 10 mm. long on back, nearly 

 as long on belly, slate-grey at base. Dorsal surface clcthed 

 with a uniform fine grizzle of sepia and yellowish-brown; no 

 indication of a darker dorsal area, but the shading is slightly 

 heavier across the lumbar region than elsewhere. An indistinct 

 tuft of whitish hairs in front of each ear. Sides, belly, limbs 

 and paws, together with the under surface of the tail, light 

 straw yellow, sharply contrasted with the colour of the dorsal 

 surface. Miller says that this description of the colour " can 

 be only approximately correct, since it is taken from the skin 

 which had been immersed in alcohol for many years. Before 



