496 Mr. O. Thomas on a 



although, of course, far more naked than in an average Mim ; 

 on the other hand, in P. lepidus the tail is smooth and hair- 

 less, as in Uromys. 



Skull very much as in P. lamia, except that the zygomata 

 are not so remarkably expanded outwards anteriorly, but are 

 of normal expansion ; nasals rather narrower ; palatal fora- 

 mina even more narrow and contracted, contrasting with the 

 more open ones of P. lepidus. Teeth of similar structure, 

 but markedly smaller, quite unusually small in proportion to 

 the size of the skull. 



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

 Head and body 120 mm.; tail 183; hind foot 25 ; ear 1(3. 

 Skull: greatest length 31*6; basilar length 25 - 5; zygo- 

 matic breadth 18; interoibital breadth 4*7 ; palatilar length 

 13*7; diastema 9 ; palatal foramina 42 x 1*5; upper molar 

 series 4'6. 



Bab. Madeu, Upper St. Joseph's R., about 50 miles N.E. 

 of Hall Sound, British New Guinea. Alt. 2000-3000'. 



Type. Old female. B.M. no. 8. 10. 8. 7. Original num- 

 ber 585. Collected June 1908 by W. Stalker. Presented 

 by Sir William Ingram, Bart. 



This species is most closely allied to P. lamia, Thos., but 

 is readily distinguishable by the more normal expansion of its 

 zygomata and its smaller teeth. 



Mr. Stalker obtained together a large number of specimens 

 of this and P. lepidus, which he did not distinguish from 

 each other, and which are, indeed, so remarkably alike ex- 

 ternally that it needs a close examination of their tails ami 

 ears to separate them. Their size, proportions, and colour 

 are quite the same, but /'. vates has a coarse-scaled tail with 

 a certain amount of hairs on it, so that it feels rough to a 

 hand passed along it from tip towards body, while the tail of 

 P. le/ndvs has smooth close-set scales without hairs, and 

 feels equally smooth whichever way it is stroked. 



LX\I. — A new Akodon from Tierra del Fuego. 

 By Oldfield Thomas. 



From our generous correspondent Mr. J. A. Wolffsohn, of 

 Valparaiso, we have recently received a tuco-tuco and a 

 mouse obtained by Dr. France in Tierra del Fuego. The 

 former may be referred to Ctenomys fueginus, Phil., but the 

 latter appears to be new, and may be called 



