1882.] MK. O. THOMAS ON RODENTS FROM PP:RU. 99 



vinces of Jaen and Chota. Tambillo is situated about 5700 feet 

 above the level of the sea, upon the eastern slope of the western 

 chain of the Cordilleras (6° S. lat.). 



Cutervo. — A town in the province of Chota, department of Caja- 

 marca, about twodays south of Tambillo, on the same slope, 9000 

 feet. 



Callacate. — A colony, 4800 feet in altitude, about 8 miles north- 

 west of Cutervo, on the banks of the river Chota, which runs into 

 the Amazon under the name of Chamaya. 



Chirhnoto^. — A colony in the valley of the Hnayabamba, a tributary 

 of the Iluallaga, in the province of Chachapoyas. It is about 5400 

 feet above the sea, upon the eastern slope of the eastern chain of 

 the Cordilleras (6'^ S. lat.). 



HuamboK — A plantation In the forest of the same name, to the east 

 of Chachapoyas and Chirimoto, 3/00 feet in altitude, on the banks of 

 the river Huambo, a tributary of the Huallaga. 



All these localities, except Tumbez, are on the northward 

 Andean extension of the Patagonian subregion, as defined by 

 Messrs. Newton and Salvin ■ ; so that we should naturally expect, as 

 indeed turns out to be the case, that most of the species would be 

 the same as those found by Mr. Louis Fraser, who collected at 

 places situated in the Ecuadorean part of this same Andean tract. 

 Tumbez is on the southward extension of the Subandean subregion on 

 the Pacific side ; but the specimens collected there are too few to 

 draw any deductions from. 



The chief interest of the collection centres in the fine series of 

 Hesperomys contained in it ; for of this difficult genus and the closely 

 aUied one Holochilus M. Stolzmann obtained just over 40 speci- 

 mens. The value of this additional material may be perceived when 

 it is remembered how very few of the specimens in the various 

 museums are preserved in spirit, or have their exact localities or 

 habits recorded. 



On account, therefore, of the fact that most of the published de- 

 scriptions have been taken either from stuffed specimens or skins, 

 I have thought it useful to give the measurements of every adult 

 specimen in this collection, even when belonging to compara- 

 tively well-known species. It must, moreover, be remembered that 

 from such a locality as Northern Peru very i'ew species of this 

 group can in any sense be called well known ; in fact, of the 1 1 

 species of Hesperomys and Holochilus here described, only two, Hes- 

 peromys longicaudatus and olivaceus, at all deserve this term ; and 

 even of these, additional measurements are much to be desired, as 

 helping to show the range of variation found among the South- 

 American Muridae. Of the 1 1 species just referred to, only one belongs 

 to Holochilus, the remaining ten being distributed among Calomys, 

 RhipidomySf and Habrothrix, three of the eight subgenera of Hes- 



' Additional information concerning these two localities maybe obtained from 

 Prof. Taczanowski's own paper on the birds collected by Mons. Stolzmann 

 (antca, p. 2). 



- Encycl. Brit. ed. 9, iii. p. 744. 



7* 



