506 



Mr. 0. Tliomas o?i ncio 



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

 brown, like l>ack. Long ninip-liairs black, tlie liglit ends, 

 when (as in the y^nng specimen) not worn oflf, 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 foot 127; ear 51. 



Skull: greatest length 116; basilar length 90; nasals 

 41x19*6; upper molar series (crowns) 17-5. 



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

 A younger specimen from Puente de Ciioculo, 1200 m. 



Ti/pe. Old male. B.M. no. 1. 6. 7. 6o. Original number 

 ]:U2. Collected 31st January, 1901, by Periy 0. Simons. 

 Presented by Oldfield Thomas. 



The Agoutis which have been named D.viriegnta, T). t'sth- 

 viica, and D. cohmhiana appear to me to be referable to 

 one species only, with several geographical subspecies. In 

 Ct^ntral America the ends of the long lump-hairs are broadly- 

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

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

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

 intense yellow or even ochraceoui {D. v. colothhiana). Tlien 

 in Peruthe light tips to the lump-hairs are again yellow'sh, 

 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 ochraccou-*. 



Finally, in Bolivia the representative form has a much 

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

 of the brilliant orange-ochraceou-j above described. 



LVIII. — yew Genera of Australasian Muiidte. 

 By Oldfikld 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 perijdieral species stand out at once as so 

 different from all others as to need removal from Mua or 

 Jipiviys before any idea of the characters of the great majority 

 of I he species can be gained. Such are 



