314 MICROTIN^ 



Characters. — Distinguished from A. r. roylei by its longer tail 

 and ears and by its hoary under parts. 



Under parts hoary, the tips of the hairs silvery grey, and usually' 

 without any trace of the ochraceous tinge so constantly present 

 in A. r. roylei. Upper surfaces of hands and feet and lower 

 surface of tail whiter than in the typical form. Tail and ears both 

 absolutely and relatively longer; the tail measurement ranging 

 between 36 and 44 mm. (instead of 33-39 mm.) and averaging 

 36-5% (instead of 33-3%) of the head and body length; the ear 

 measurement ranging between 14 and 15-5 mm. (instead of 

 11-13 mm.). 



For external and cranial measurements, see tables at end of 

 volume. 



5. Alticola albicauda True. 



1894. Arvicola albicauda True, Proc. U.S. Nat. Mus., 17, p. 12. 



1896. Microtus [Alticola'] albicavda Miller, N. Amer. Fauna, No. 12, 



p. 54, and Proc. Acad. Nat. Sci. Philadelphia, 1899, p. 294; 



Wroughton, " Summary," J. Bombay N.H.S., 27, 1920, p. 59. 



Type.— U.S. Nat. Mus., No. fglf | ; adult female, skin and 

 skull, collected, Dec. 19, 1891, by Dr. W. L. Abbott. 



Type locality. — Braldu Valley, Baltistan. 



Range. — Baltistan ; at present known only from the Braldu 

 Valley and the Nahr Nullah, Skardu, at an altitude of about 

 12,000 feet. 



Characters. — General external appearance much as in A. 

 llanfordi, but readily distinguished by its much shorter, entirely 

 or almost entirely white tail, and its peculiarly modified m^. 



Fur moderately dense and about 15 mm. long upon the back. 

 Colour of upper parts pale reddish-grey, the hairs dark plumbeous 

 at the base, with a subterminal ring of pale yellow, and brown tips, 

 the peculiar pale tint of the back being produced by the mingling 

 of these three colours. Under parts (together with the upper lip) 

 pure white, the hairs with grey bases. Ears clothed with long 

 hairs, those of the margin pale orange brown. Tail short, its 

 length equal to 28-30% of the head and body measurement; 

 more closely haired than in A. blanfordi, pure white (in the type) 

 above and below, and with a terminal pencil 12 mm. in length. 

 Hands and feet pure white ; thumb with a " rudimentary " claw; 

 soles densely haired behind the pads. 



In three specimens from the Nahr Nullah, Skardu, collected 

 in August, the backs are dull yellowish-grey ; the under parts are 

 white, darkened by the slaty bases of the hairs, and sharply 

 contrasted with the flanks ; the tail, clothed with long stiff 

 hairs, which form a moderately thick terminal pencil of about 

 10 mm. in length but do not quite conceal the annulations, shows 

 a feeble trace of bicoloration, its upper surface being very faintly 

 tinged with brown. In all other respects these specimens agree 



I 



