1901.] Allen, Mammals from Peru. . 45 



hind foot, 25 ; ear (in dry skin), 24.5. A second specimen, ' young adult' fe- 

 male, is somewhat smaller, as follows : Total length, 191 ; head and body, 70, 

 tail, 121. 



Skull. Similar in general features to that of P. boliviensis, but the interor- 

 bital and rostral portion slenderer and relatively longer, and the bullse rela- 

 tively smaller ; whole skull much smaller and more lightly constructed. Total 

 length, 28 ; basal length, 22 ; palate, 12 ; nasals, 11.5 ; zygomatic breadth, 15 ; 

 interorbital breadth, 4 ; mastoid breadth, 12.5 ; palatal foramina, 6x2; upper 

 tooth-row, 5.7. 



This species is based on two specimens, an adult female and a 

 young adult female, the latter taken at Tirapata, Oct. 20, and the 

 former at Osila, between San Antonio and Tirapata, Oct. 20. 

 The collector states in his notes that they were taken at the same 

 localities with P. boliviensis, and that they had the same habits. 

 One was taken in a trap and the other shot while feeding late in 

 the afternoon. 



In size and proportions P. osiJce. resembles the P. amicus 

 group, especially P. amicus montanus Thomas, from Urumarca, 

 northern Peru, from which it differs in being larger, with a longer 

 tail, darker coloration, and dusky brown ears. 



1 6. Akodon caliginosus ( Tomes). Represented by 19 speci- 

 mens, 15 of which are adult and 4 young. All are from Inca 

 Mines. The young examples include one about one half grown, 

 one about one third grown, and one nursling. In coloration 

 they scarcely differ from the darker adults. The olivaceous tint 

 above in the adults varies somewhat in different specimens, being 

 darker or lighter according to the extent of the yellowish rufous 

 tipping the hairs. 



*i7. Akodon pulcherrimus Thomas. Five specimens, of 

 which one is from Tirapata, and two each from Limbana and 

 Crucero. 



The collector's measurements of these specimens are as fol- 

 lows : Total length, 167 (162-176) ; head and body, 92 (89-96) ; 

 tail, 76.5 (68-82) ; hind foot, 24 (22-25). 



Mr. Thomas's description fails to mention the very prominent 

 deep rusty fulvous spot on each side of the nose, but it otherwise 

 exactly fits the present examples, except that his type considera- 

 bly exceeds in size any of the specimens in this series. These 

 specimens are, however, from near the type locality and are not 

 likely to prove different from those described by Mr. Thomas. 



