1899.] NATURAL SCIENCES OF PHILADELPHIA 293 



9. MicROTUs ACROPHiLUS sp. nov. (Ladak side of Kara Koruin 

 Pass. ) 



These nine species may be distinguished ])y the following char- 

 acters : 



Key to Species of Alticola.* 



Under parts dark. 



m 3 with 4 salient angles Microtus wynnei. 



m 3 with 6 salient angles. 



Hind fool, 22 mm Microtus roylei. 



Hind foot, 20 mm. ... ... Microtus montosa. 



Under parts whitish. 



Back bright ferruginous brown . . . Microtus stoliczkamis. 

 Back gray or pale fawn. 



Tail vertebrse over 45 mm Mi&rotus hlanfordi. 



Tail vertebrae under 40 mm. 

 m 3 with 6 salient angles. 



m i with 10 salient angles. . . . Microtus stracheyi. 

 m 1 with 8 salient angles. . . . Microtus alhicauda. 

 m 3 with 5 salient angles. 



Teeth heavy; posterior loop of m 3 forming much less 



than half of crown Microtus acrophilus. 



Teeth light; posterior loop of m 3 forming at least half 

 of crown Microtxis cricelulus. 



Microtus montosus (True). 

 1S94. Arvicola montosa True, Proc. U. S. National Museum, xvii, p. 

 11. May 8, 1894. 



Type locality. — Central Kashmir. Altitude, 11,000 feet. 



Specimens collected. — Dr. Abbott obtained only one specimen of 

 this species, the type, a half -grown male. 



Remarks. — Microtus montosus is very doubtfully distinct from M. 

 roylei, also from Kashmir. The type and only known specimen is 

 young — scarcely more than half-grown — so that its true characters 

 cannot be determined with certainty; but I am unable to see that 

 it differs from 31. roylei, as described by Blanford, in any way 

 not to be accounted for by its immaturity. 



^ In part compiled from Blanford's papers on the group. 



