106 MR. O. THOMAS ON RODENTS FROM PERU. [Jan. 1/, 



mys has been recorded \ notwithstanding the tropical climate of 

 central and northern South America and the innumerable forms 

 into which the Vesper-mice have been developed. 



Among the Old-World Muridse instances of the development of 

 spines are extremely numerous, though their presence would seem 

 often to be variable, the spines being apparently shed and renewed ac- 

 cording to the season of year". In the case of this Peruvian Vesper- 

 mouse, however, it is scarcely likely that there could be any shedding 

 of spines according to season, since at Huambo, only 6 degrees south 

 of the equator, there can be but very little appreciable change of 

 season at all. Moreover, as far as regards the distinctness of this 

 species, there appears to be no Calomys as yet described with the 

 colours and proportions of H. spinosus, even if we ignore the presence 

 of the spines as a specific character. 



8. Hesperomys(Rhipidomys)leucodactylus, Tschudi, Fauna 

 Peruana, p. 183, Taf. xiii. fig. 2 (1844). 



H. latimanus. Tomes, P.Z.S. 1860, p. 213. 

 a. Huambo, 3700', April or May 1880. 



Head and Forearm Ear-concb, Muzzle 



body. Tail. Hind foot. and hand, length. to ear. 



«. ? .. 4-85 6-5 1-1 1-4 -5 M7 



The single specimen of this species is rather paler-coloured than 

 Tschudi' s type, which I have examined in the Berlin Museum ; it is 

 otherwise, however, quite identical, all the more important characters 

 agreeing exactly. The following is a short description of Mons. 

 Stolzmann's specimen : — 



Fur soft and close. General color above pale brownish grey, 

 below white. Dark colour of the back continued down to the meta- 

 carpals and metatarsals ; toes white. Ears without a projection on 

 their anterior edge. Tail quite unicolor, dark brown, with the hairs 

 increasing in length to its tip, where they form a distinct pencil. 

 Feet remarkably short and broad, sole-pads very large, round and 

 smooth. Fifth hind toes reaching to the middle of the second pha- 

 lanx of the fourth toes. Whiskers very numerous, black. Mammae 

 six, one pectoral and two inguinal pairs. 



" Several individuals of this species were caught on the palmwood 

 roof of the house in which I was living. They gnawed to pieces 

 all leather articles, such as saddles and bridles, and used the frag- 

 ments to build their nests with. One of these, made of paper torn 

 from a book, was built in the folds of a mosquito-net." 



^ Limd (Blik p. Bras. Dyrev. iii. p. 277, 1841) described a Mits setosus from 

 Minas Geraes as having spines in the fur ; but this is now generally admitted 

 to have been founded on a specimen of Mus alexandrinus, Geoff., an introduced 

 species which seems to be very common in Brazil. 



a Cf. P. Z. S. 1881, p. 540. 



