COLLECTION OF MAMMALS FROM TIBET. 803 



Size about that of C. phceus. General colour above pale fulvous grey, greyer 

 than in C. phceus. 



Each hair is slate-grey at its base, fulvous for about \ of its distal end and 

 with a black tip. Over the head and fore part of the body the fulvous por- 

 tion of each hair is the more conspicuous, but on the hinder part of the back 

 the dark tips predominate and a faint dark median dorsal line may be traced. 

 The underparts are pure white, the hairs being slate-grey at their base. The 

 line of demarcation between the upper and under parts, although abrupt, is 

 very uneven in outline. The feet are but scantily clothed with hair and are 

 white. The tail is moderately long and stout, well clothed with dark-brown 

 hairs above and white hairs below ; the tip is white. 



The whiskers are for the most part black with a white tip, some shorter ones, 

 however, being entirely white. 



The skull resembles somewhat closely that of C. phceus, but is slightly larger 

 and the brain-case more inflated and rounded. The chief points of difference 

 when viewed from below, are the greater width of the basioccipital and the 

 much flatter and smaller bullae in the new species. A bove there is a slight, 

 although very constant, difference in the hinder margin of the parietals, which 

 are practically straight in outline ; whereas in C. phceus there is a sharp turn 

 backwards when about two-thirds of their length from the middle line. 



Dimensions (of type when in spirit). — Head and body 87 mm.; tail 40 ; hind 

 foot 17 ; ear 16. 



Skull. — Greatest length 28'5 mm.; basal length 24 ; palatal length from hen- 

 selion 12 ; interorbital breadth 5 : greatest breadth of brain-case 12*5 ; width 

 of basioccipital at anterior end of auditory bullae 3. 

 Habitat. — Lhasa, Tibet. 



Type— B. M. 5, 4, 6, 4. Collected at Lhasa, Tibet, by Capt. H. J. Walton, 

 I.M.S. 



The darker colour of the hinder part of the back combined with the general 

 much greyer coloration, and in addition the somewhat longer and stouter tail 

 form characters by which this species may be distinguished from C. phceus. 

 The animal, according to Capt. Walton, was extremely common, and was 

 swarming in one of the shrines of the Jo Khang Cathedral at Lhasa. 

 Micbotds (Phaiomys) waltoni. 



Microtus (Phaiomys) waltoni Bonhote. Abstr. P.Z.S., No. 22, p. 14, Nov. 

 21, 1905. 



a. $ ad. Lhasa, Tibet. 



Slightly smaller in size than Ph. blythi, to which it is by skull-characters 

 closely allied, though widely differing in colour. General appearance above 

 fulvous grey, slightly greyer over the anterior part of the body ; below very 

 pale buff. Each hair is slate- grey from its base and for the greater part of its 

 length, with a fulvous subterminal portion and dark tip. On either side 

 between the limbs, the dark tips are absent, leaving a clear fulvous patch. 

 Interspersed in the fur are a few thin black bristles. The feet are whitish, 

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