474: On Small Mammals from Western Yunnan. 



The following are the external measareraeuts of a male of 

 this species, which was described from a skull onl}' : — 



Head and body 110 mm. ; tail 01 ; hind foot 19; ear 11. 



In colour M. loardi is quite like M. chinensis^ as was to 

 be expected. 



11. Microtus (^Anteliomys) custos, Thos. 

 1. A-tnn-tsi. 12,000'. 



12. Microtis [Eothenomys) melanogaster milelus, subsp. n. 



cJ . 10 miles W. of Yang-pi, W. Yunnan. 7000'. 



Near M. melanogaster eleusis, but bulkier throughout. 



General external characters, including colour and the 

 greater length of tail, as in the subspecies eleusis. Size, 

 however, somewhat greater. 



Skull markedly larger and heavier than that of eleusis, the 

 upper outline much more bovved, and the frontal height 

 therefore considerably greater. Interorbital region lieavy^ 

 convex, its edges not ridged. Brain-case smooth, the angles 

 and ridges little developed. Anterior palatine foramina more 

 widely open tiian in eleusis. Bullae slightly smaller. 



Molars larger than in eleusis, but their structure quite as 

 in that form ; m^ similarly with four salient angles on its 

 inner side. 



Dimensions of the type (measured in the flesh) :■ — 



Head and body 114 mm. ; tail 48 ; hind foot 19 ; ear 13. 



Skull : condylo-incisive length 25 ; basilar length 22*2 ; 

 zyo'oraatic breadth 15'6 ; nasals 7*6 : interorbital breadth 4'5; 

 breadth of brain-case 12'4 ; height of forehead above alveolus 

 of 7n- 8'4 ; palatilar length 12 ; palatal foramina 5xl'8; 

 upper molar series (crowns) G'2. 



Uab. as above. 



Type. Adult male. B.M. no. 14. 10. 23. 32. Original 

 number 34. Collected 28th February, 1914. 



This vole has a skull so much larger and heavier tlian that 

 of either true mel tnogaster or the sub-pecies eleusis that it 

 might be thought distinguishable as a full species. But on 

 the analogy of the races of Microtus a;^restis, as admitted by 

 Mr. Miller, we may for the present allow an equal range of 

 variation for M. melanogaster, especially as the distribution 

 of the group is probably continuous. The difference in w' 

 which distinguishes eleusis and miletus from true melano- 

 gaster is also paralleled by that in m^ characteristic of 

 Microtus a g rest is e.vsul. 



