1882.] MR. O. THOMAS ON RODENTS FROM PERU. 1 1 I 



I am not quite certain about the identity of these specimens with 

 Mr. Tomes's Ecuadorean species, as H. caliyinosus is described as 

 being .5 inches long, with nearly naked ears and feet, but by measur- 

 ing the largest individual of the present series along the curves, a 

 length of nearly 5 inches may be obtained ; and as the colours and 

 other dimensions agree very fairly, I prefer to regard them as 

 H. caliginosus, rather than to describe them as new. 



The following is a short description of these specimens :— Fur 

 very soft, of medium length. General colour above dark grizzled 

 orange-black, the colour resulting being as dark as in II. ohscurus, 

 Waterh. Belly pale yellowish white, the bases of the hairs grey. 

 Ears, feet, and tail covered with short dark brown hairs. Ears with 

 a rounded projection on their anterior margin. Fifth hind toes 

 reaching to between the base and the middle of the first phalanx of 

 the fourth toes. Tail uniformly black all round, vipperside of feet 

 granulated with black, and the soles of the hind feet also deep black. 

 This blackness of all the extremities forms a ready means of distin- 

 guishing the present species from the preceding one, in which the 

 tail is brown above and grey beneath, and the soles have scarcely a 

 tinge of black. 



The British Museum also possesses a specimen certainly identical 

 with these Peruvian ones, which was collected by Mr. T. K. Salmon 

 at Concordia, Medellin ; so that, as Ecuador is just between that loca- 

 hty and the present one, the probability of M. Stolzmann's speci- 

 mens being the true ff. caliginosus is greatly increased. 



" This is the most diurnal species of all, and on that account is 

 very subject to the attacks of CEstrus. The base of its tail is 

 naked and white ; and the fly deposits its eggs on this spot, as may 

 be seen in those specimens which contain the larvae, or from which 

 the latter have escaped." 



In addition to the above notes on the Rodents collected by M. 

 Stolzmann, it may be useful to give the localities and dates for the 

 three species of Opossum obtained by him. These are: — 



14. DlDELPHYS NTJDICAUDATA, Geoff. 



a, b. $ and young, Chirimoto, 5400', July 1880. 



15. DlDELPHYS CINEREA, Tcmm. 



a. ?, Chirimoto, 5400', July 1880. 



16. DlDELPHYS MURiNA, Linn. 



a. $, Tambillo, 5800', Feb. 1878. 



h, c. 2 and <^ > Tumbez, sea-level, June 1876. 



