154 



" Tlie following species of Rodents were also contained in the col- 

 lection, viz. Myopotamiis coypus, Poephagomys ater, Octodon Cumingii, 

 Mus Darivinii, Mus megalonyx (a new species, the characters of which 

 Mr. Waterhouse pointed out), and the Mountain Viscacha (Lagotis 

 Cuvieri, Bennett) . Severai specimens of this last-mentioned animal 

 ■were procured by Mr. Bridges on the Chile side of the Andes, and 

 upon comparison they prove to be specifically identical ■vvith an indi- 

 vidual formerly sent by the šame gentleman and which was found in 

 the vicinity of Mendoza. The Viscacha, Mr. Bridges' notes statė, 

 ' confines itself to the elevated parts of the Andes, always inhabiting 

 rugged and precipitous mountains where there are natūrai caves or 

 immense stones rolled in confusion, amongst \vhich it makes its 

 abode.' It has a very extended range, he having found it in Bolivia 

 in south lat. 20° to 22°, whilst the specimens laid before the Meeting 

 vvere from the province of Aconcagua, near ' Los ojos de Agua.' 

 Mr. Bridges further remarks that it seldora leaves its abode during 

 the daytime, but coraes out to feed upon the herbage either before 

 sunrise or late in the evening. 



" Severai specimens of Didelphis elegans were also sent home by 

 Mr. Bridges, •vvho statės that they were procured for him by the na- 

 tives in the province of Aconcagua, where they were caught in traps 

 baited with meat, and which were placed for that purpose in the 

 vicinity of old hedges and vineyards. Mr. Bridges also calls atten- 

 tion in bis letter to the differences observed in the sexes of this ani- 

 mal, the female being considerably smaller than the malė, and re- 

 markable for having the tail very thick and fleshy. It is known to 

 the natives by the names ' Comadrejo' and ' Llaca.' " 



The following is Mr. Waterhouse's description of the new species 

 of Mus (which he places in the section Hesperomys) contained in the 

 collection : — 



Hesperomys megalonyx. Hesp. suprd, cinerascenti-fuscus, subtUs 

 cinereo-alhus ; auribus mediocribus ; pedibus anticis unguibus mag- 

 nis armatis ; caudd brevi, pilis minutis obsitd. 



unc. lin. 

 Longitudo ab apice rostri ad caudse basin .... 4 4 



. caudk 1 6 



auribus O 85 



tarsi digitorumque O 11^ 



ab apice rostri ad basin auris .... 1 2^ 



Hab. Chile. 



This little mouse evidently belongs to the genus Hesperomys, but 

 it difFers from any species hitherto described in having stronger fore- 

 feet, and these furnished with long claws, exceeding the toes in 

 length. The inner toe or thumb is furnished with a distinct pointed 

 claw. ITie fur is very soft, and in the upper parts of the body nearly 

 of a uniform grey-brown tint, though the hairs of the ordinary fur 

 are annulated \vith pale brown ; at the base these hairs are of a deep 

 slate-grey colour. The under parts of the body are grey-vvhite, but 

 the hairs are deepish grey at the root, and on the chest there is a 

 brownish mark. The chin is white ; the feet are pale brown, but the 



