tiew Svxtth- American Maininah. IT* 3 



bra ill-case 1 7'.') x lo'T) ; jialate It ii;:tli fidiii liciisclion KM; 

 diastema iS 7 ; palatal toiaiiiiiia HG x 2'0 ; K-ii^mIi of U|ij>ei- 

 molar series '). 



Ilah. Meiida. 'V\\n- from " Las Ve-^as ilel (.'Iiaina," alt. 

 1400 m. 



Tifi>e (f.-inale). l'...M. ii-.. Hi). 12. 1. 1. Colleclecl 14tli July, 

 18!)6, by S. Hiicefio. 



Three skins of this species have been lyinp for some time 

 among Sr. Briceuo's specimens of Rh. venezuelce, to which I 

 bad supposed them to be referalile. Now, however, a closer 

 txamination shows that they belong to quite a different 

 s;j)eeies, distinj,'uislied bv the charai'ters above mentionel. 



Nkacomys, gen. nov. 



Ttipe. Oryzo»ii/s spinosiis, Thos. P. Z. S. 1882, p. 105. 



Further knowledge of South-American Muridas iiaving 

 faileil to reveal any sjjecies of " Oryzomys " intermediate 

 between the Acoiijys-Wkfi ^' I/esperoinys^^ sjiinosus described 

 b} nie eighteen years ago and the ordinary soft-furred species 

 of Oryzomys, I now think it advisable to give that anomalous 

 form a special generic name. 



To the cranial characters described previously it may be 

 added that the skull is low and broad, the supraorbital 

 edges distinctly but not excessively beaded, the interparietal 

 of medium size, the bulhv small, and the palatal foramina are 

 unusually short. The molars are of typical (h-yzoinyft Btructure, 

 but are small in proportion to the general size of the skull. 



Neacomys ftpi'nnsus tenuipes, subsp. n. 



Very similar to A\ s. typicus in general appearance, spini- 

 ness, and colour, but the general tone rather less vivid, the 

 back darker, and the sides shading off into fulvous rather than 

 rufous. Belly-hairs j)ure white or dull white, not slate-based, 

 though this latter characteristic proves to vary in S. s. typicua. 

 Feet very much smaller than in typicus^ averaging about 

 2 millim. shorter, and very markedly more slender than in 

 that form. 



Dimensions of the tyjje (an adult female, measured in 

 skin) : — 



Head and body 76 millim, ; tail 93 ; hind foot 20; ear 12. 



J/fi/>. (iuaquimay, near Bogota. Also from " Qiiebrada 

 negra " and " Magdalena Valley." 



Type. B.M. no. 99. 10. :^. 74. Collected by G. D. Child, 

 16th January, 1896. Five specimens examined. 



Five specimens of the typical form from Peru have the 

 hind feet 22-2, 22-2, 22-4, 221^, and 23 millim. ; the longest 

 foot among the Bogota series is 20'5 millim. in length. 



