326 MICROTINiE 



Two species are at present recognized — Alticola (Platycranius) 

 strelzou'i Kascenko and A. (P.) atliarius Pallas; but the differ- 

 ences between these forms are very slight and in all probability 

 both will eventually have to be treated as subspecies of A. (P.) 

 alliarius. 



1. Alticola (Platycranius) strelzowi Kascenko. 



1840. Arvicola aUiaria Ev^ersmann, Ecrecr. HcTopiH OpeH6yprc. 

 Kpaa, 1, p. 168. Not Mus alliarius Pallas, 1779. 



1900. Microtus strelzowi Kascenko, Bull. Imjj. Tomsk Univ., 16, 

 p. 50. 



1901. Microtus {Platycranius) strelzowi Kascenko, Ann. Mus. Zool. 

 Acad. Imp. So. St. Petersbourg, 6, p. 201. 



1901. Microtus strelzowi desertorum Kascenko, Ann. Mus. Zool. Acad. 

 Imp. iSc. St. Petersbourg, 6, p. 206 {nam. nov. for Arvicola alliaria 

 Eversmann) ; type : Zool. Mus. Acad. Sc. Russia (Leningrad), 

 No. 1471. 



Co-types. — Zool. Mus. Acad. Sc. Russia (Leningrad), Nos. 

 13261-3, and perhaps in the Museum of Tomsk University. 



Type locality. — Altai. 



Range. — Altai Mountains, Central Asia. Limits of distribution 

 unknown. 



Eversmann's specimen (Leningrad, No. 1471) is reputed to 

 have come from the Orenburg district ; for this reason Kascenko, 

 regarding it as representing a " semi-hypothetical steppe sub- 

 species," has renamed Eversmann's " Arvicola alliaria," as 

 indicated above in the synonymy. But no other trace of such an 

 animal has been found in the Orenburg district; and neither 

 Kascenko nor Montagu (who kindly examined Eversmann's 

 specimen for me) can find any character distinguishing No. 1471 

 from the co-types of A. (P.) strelzowi. In all probability No. 1471 

 came from the Altai and some mistake has been made with 

 reference to its locality. 



Characters. — Size medium ; hind-foot 20 to 22 mm. ; condylo- 

 basal length up to 29-1 mm. General outward appearance as in 

 normal Alticola. Fur very soft and fine in adolescent specimens, 

 somewhat harsher in fully adult individuals. Ears large, fully 

 haired as a rule, but in some specimens naked towards the tip 

 externally (? pathological or seasonal). Hands and feet normal; 

 thumb very small, bearing a minute flattened nail ; palmar pads 

 five; plantar pads six; soles densely haired posteriorly. Tail 

 long, from about one-third to half the length of the head and 

 body; densely clothed with long, stiff, adpressed bristles, which 

 completely conceal the annulations and form a long and dense 

 terminal pencil. Mammse, 2 — 2 = 8. 



Colour of upper parts ashy grey, more or less irregularly 

 brightened by the yellowish or slightly rufous subterminal bands 

 of the hairs, inconspicuously and to a varying extent " lined " 

 by the longer black hairs and dusky hair-tips. In younger 



