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Show 106 MR. O. THOMAS ON RODENTS FROM PERU. [Jan. 17, mys has been recorded1, 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-AVorld Muridae 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 according to the season of year2. In the case of this Peruvian Vesper-mouse, however, it is scarcely likely that there could be any shedding of spiues 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 M a y 1880. Head and Forearm Ear-conch, Muzzle body. Tail. Hind foot. and hand, length. to ear. «. 2 •• 4*85 6-5 1-1 1-4 -5 1-17 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 metacarpals 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 phalanx 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 fragments to build their nests with. One of these, made of paper torn from a book, was built in the folds of a mosquito-net." 1 Lund (Blik p, Bras. Dyrev. iii. p. 277, 1841) described a Mus 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 alcxandrinus, Geoff., an introduced species which seems to be very common in Brazil. a Cf. P. Z. S. 1881, p. 540. |