324 MICROTIN^ 



the under surface is brown like the back, and that there are only 

 five tarsal pads, statements which seem to indicate that the 

 specimen represents a species of Hyperacrius. 



12. Alticola lama Barrett-Hamilton. 

 1900. Microtus [Alticola) lama Barrett- Hamilton, P.Z.S., 1900, 

 p. 196. 



T?/;)e.— B.M., No. 97.1.21.3; adult skin and skull (defective), 

 collected Aug. 1896, and presented by Captain H. H. P. Deasy. 



Type locality — Twenty-five miles S.E. of Lake Arucho. 

 Western Tibet. Altitude 16,000 feet. 



Range. — Western Tibet ; known only from the vicinity of the 

 type locality at altitudes of 16,000 and 17,800 feet. 



Characters — Outwardly quite like A. stracheyi, from which it 

 is distinguished chiefly by its larger and deeper braincase and 

 larger auditory bullae. Hind-foot 18 mm. 



Cheek-teeth. — In the type, m^ on each side possesses a rather 

 well-developed third inner angle ; but this is possibly only an 

 individual abnormality. In a second skull from the type locality 

 m^ is exactly as in many examples of A. stracheyi, its third 

 inner angle being obsolete and represented by no more than a 

 vestigial bulge on the inner side of the long posterior loop. A 

 third specimen from a slightly higher locality is younger and 

 its m^ shows the minute vestige of a third inner angle com- 

 monly found in young specimens of A . stracheyi. 



For external and cranial measurements, see tables at end of 

 volume. 



Remarks. — The status of A. lama will remain doubtful until 

 further material has been obtained. The specimens upon which 

 it is based are in poor condition without proper measurements 

 and with broken skulls. Not improbably it will turn out to be no 

 more than a subspecies of A. stracheyi, intergrading near the 

 western frontier of Tibet with the typical form. 



13. Alticola acrophilus Miller. 

 1899. Microtus acrophilus Miller, Proc. Acad. Nat. Sci. Pliiladelphia, 



1899, p. 296 (.subgenus Alticola). 

 1920. Microtus [Alticola) acrophilus Wroughton, J. Bombay N.H.S., 



27, p. 59. 



Type~V.^. Nat. Mus. No. 62162; adult female, skin and 

 skull, collected July 25, 1893, by Dr. W. L. Abbott. 



Type locality. — Ladak side of the Karakorum Pass. Altitude 

 17,000 feet. 



Range — Known only from the type locality. 



Characters. — Closely related to A. stoliczkanus, from which it 

 is readily distinguishable by its shorter tail and much paler 

 colour. 



m 



