Rodenfs from N.W. Yunnan. 515 



Tj/pe as above. 



" Caught on mossy bank in Abies forest." — F. K. TT". 



The nose of this sjieciinen is elongate, approximating to 

 tliat of (Iropsi/us, and there is no doubt the short-nosed 

 condition described and figured by Milne-Edwards was due 

 to the vicissitudes his specimen had undergone. 



This is the first examj)Io of the distinct genus Scapfonyx 

 that has come to the British Museum, David's specimen in 

 the Paris Museum having remained unique up to the present 

 time. Tiianks to the courtesy of Prof. Trouessart I liave 

 had an opportunity to compare the skulls of the two, and 

 find such diflferences in the j)roportions of the premolars as to 

 indicate that the Mc-Kong form is subspecifically distinct. 

 All other characters would seem to be the same. 



With regard to the dentition of Scaptonyx, it is evident 

 that in one res{)ect at least the fornnila given by Milne- 

 Edwards is erroneous, for while correctly identifying the 

 upper canine, he has not noticed that the long caniniform 

 tooth of the lower jaw bites behind instead of in front of it, 

 and is therefore — as in the true moles — the first premolar. 



Putting the formula, therefore, in the same manner as 

 those of the other members of the group recently published"^, 

 we should have : — 



y 1.2.3 r, 1 p 1.2.3.4 ^ 1.2.3 11 , , o a:, 

 •*• 0.2.3' ^'* 1> ^ ' 1 . 2.3.4» ■"■^* 1.2.3 — 10 "^ ^^' 



The number of teeth is the same as in 3Iogera, there being 

 one less lower incisor than in Taljxi. Whether the missing 

 incisor is «i or 23 remains to be proved, both for Scaptonyx 

 and Mogera, but the indications of the milk-dentition seem to 

 show that in Dymecodon and Urotrichus at least it is ii, as 

 formulated above. 



So far as its dentition is concerned, Scaptonyx is in an 

 interesting halfway condition between the Talpa group, in 

 which the canine above and caniniform premolar below are 

 dominant, the incisors being small, and Urotrichus and the 

 American moles, in which the main work is thrown on the 

 anterior incisors, both above and below. Here there is appa- 

 rently little difference in functional importance between the 

 competing teeth. 



2. Marmota rohusta, M.-Edw. 

 ? . 20 (young). A-tun-tsi. 15,000'. 



* P. Z. S. 1912, p. 131. 



