506 Mr. O. Thomas on neio 



extreme bases. Muzzle, ears, and nape grizzled tawny- 

 brown, like back. Long ramp-hairs black, the light ends, 

 when (as in the young specimen) not worn off, dull ochra- 

 ceous buff. Inner aspect of upper arms and thighs ochre- 

 yellow. Hands and feet black, with a few fine tawny 

 tickings. 



Dimensions of the type (measured in flesh) : — 



Head and body 560 mm.; tail 25; hind toot 127; ear 51. 



Skull: greatest length 116; basilar length 90; nasals 

 41xl9'6; upper molar series (crowns) 175. 



IJab. Yungas, Bolivia. Type from Chimosi, alt. 1700 m. 

 A younger specimen from Puente de Choculo, 1200 m. 



Type. Old male. B.M. no. 1. 6. 7. 63. Original number 

 i;U2. Collected 31st January, 1901, by Perry O. Simons. 

 Presented by Oldfield Thomas. 



The Agoutis which have been named D.viriegota, D. nth- 

 mica, and D. colombiana appear to me to be referable to 

 one species only, with several geographical subspecies. In 

 Central America the ends of the long lump-hairs are broadly 

 yellowish, like those of the rest of the body (D. v. isthmica) ; 

 then in Colombia and Ecuador the rump-hairs are more or 

 less white-tipped, the general body-colour being often a more 

 intense yellow or even ochraceous {D. v. columbiano). Then 

 in Peru the light tips to the lump-hairs are again yellowish, 

 but are much narrower than in isthmica, and are often 

 entirely worn off. Tschudi himself speaks of the tips as 

 whitish, but this is probably due to the rest of the animal 

 being a stronger ochraceous. 



Finally, in Bolivia the representative form has a much 

 darker and more tawny body-colour and the under surface is 

 of the brilliant orange-ochraceous above described. 



LVIII. — Xew Genera of Australasian Muiida?. 

 By Oldfield Thomas. 



(Published by permission of the Trustees of the British Museum.) 



On attempting to arrange the Australasian Muridse hitheito 

 referred to " Mus " in genera of a more modern character, I 

 find that certain peripheral species stand out at once as so 

 different from all others as to need removal from Mus or 

 Epimys before any idea of the characters of the great majority 

 ot the species can be gained. Such are 



