1882.] MR. O. THOMAS ON RODENTS FROM PERU. 107 



9. Hesperomys (Rhipidomys) pyrrhorhinus, Pr. Max. 

 Abbildungen, Taf. 27 (1822-26) ; Beitr. ii. p. 422 (1826). 



Mas mystacnlis, Lund, Blik p. Bras. Dyrev. iii. p. 2/9 (1841). 



H. leucodactylus^, Natt., "Wagn. Wiegm. Archiv, xi. 1, p. 147 (nee 

 Tschudi) (1845) ; Miinch. Abhandl. v. p. 310 (1850). 



E. macrurus, Gerv. Casteln. Amor, du Sud, Mamni. p. 3, pi. 16. 

 fig. 1 (1855). 



«, b. Tambillo, 5800', February 1878. 



Forearm Ear-conch, Muzzle 



Hind foot, and hand. length. to ear. 



1-2 1-55 71 1-3 



1-13 1-4 70 1-19 



The following is a description of the two specimens ia the col- 

 lection : — 



Fur long and very soft, not mixed with longer harsher hairs. 

 General colour above rich rufous, quite hiding the dark slate- 

 coloured bases of the hairs. Head similar but paler. Belly-hairs 

 half slate-colour, half pure white. Ears covered with short black 

 hairs. Whiskers black. Fore feet with the metacarpals brown and 

 the digits white. Hind feet with the metatarsals pale orange- 

 coloured and the digits brown. Tail very long, the basal half inch 

 covered with the red-tipped body-hairs, the remainder imiformly 

 dark brown above and below, the hairs, which are black, forming 

 rather less of a pencil than usual. Ears without a projection on the 

 anterior edge. Feet rather long for the subgenus, though shorter 

 than in ordinary Hesperomyes. Foot-pads large, smooth and rounded. 

 Fifth hind toes as in H. leucodactylus . Mammae 6, one pectoral, 

 .and two inguinal pairs. Incisors both above and below orange- 

 coloured, broader than in other RMpidomyes. 



It will be seen that there are certain discrepancies between the 

 above and the original description. The true H. pyrrhorhinus is 

 said to have a reddish-yellow back and a pure white belly, as also 

 has a specimen from Bahia, probably the type, oiH. macrurus, Gerv., 

 in the British Museum. The original specimens of H. pyrrhorhinus, 

 moreover, were also obtained in Bahia, on the eastern side of South 

 America. However, without knowing more of the forms inhabiting 

 the intermediate country, I do not care to describe M. Stolzraann's 

 specimens as new. 



" Lives in trees." 



These last two species belong to a very distinct subgenus. Its 

 chief characters may be thus expressed : — Form Dormouse-like. 

 Tail long, with the hairs generally forming a pencil at the tip. 

 Feet short and broad ; the foot-pads large, smooth and rounded, but 

 not standing up much above the sole, evidently adapted for climbing. 



•■ Burmeister (Eepubl. Argent, p. 223) refers this name to H. angouya, 

 Desm. ; but, judging from Wagner's descriptions, I think there can be no doubt 

 that it is the present species. He distinctly refers to the pencil of longer hairs 

 at the tip of the tail, wliich is quite absent in H, anyouya. 



