i goo.] Allen, On Mammals Collected in Southeastern Peru. 22$ 

 ii. Oryzomys keaysi, sp. nov. 



Type, No. 16062, $ ad., Juliaca, Peru, altitude 6000 feet, Jan. 7, 1900; 

 coll. H. H. Keays, in whose honor the species is named. 



Above yellowish brown, varied with black-tipped hairs, especially on the 

 middle area of the back, lighter and more yellowish on the sides, and slightly 

 grayish on the front of the head and nose, darker, almost blackish, around the 

 eyes and at the base of the tail ; below grayish white, in some individuals with a 

 slight yellowish tinge on the breast ; ears very large, dark brown, thinly clothed 

 with short blackish hairs ; feet dull grayish brown, the toes of the fore feet and 

 the hind feet nearly naked ; palms dull light brown, soles blackish brown ; tail 

 very long, naked, rather dark brown above, a little lighter brown below. 



Measurements. Total length (type), 355 mm.; head and body, 158 ; tail, 197 ; 

 hind foot, 38, without claws, 35.8 ; ear (in dry skin), from crown, 18, from 

 notch, 21, by 20 in width. Another specimen, an adult male, measures the 

 same ; three other ' adults' range as follows ; total length, 305-335 ; head and 

 body, 150-162 ; tail, 155-174 ; hind foot, 32-34. 



Skull. The skull is very heavily built in all its parts, with the supraorbital 

 bead and parietal ridges strongly developed ; and the interorbital plane is de- 

 cidedly depressed in old specimens. Palatal foramina short and broad. 



Total length (of type), 38.3; basal length, 29.5; nasals, 15; zygomatic 

 breadth, 19 ; mastoid breadth, 14.3 ; interorbital breadth, 6 ; diastema, 9.3 ; 

 palatal foramina, 6.5 x 3 ; upper molar series, 6. Several other rather younger 

 skulls range in total length from 35-37. 



This species is based on a series of five specimens, all taken at 

 Juliaca, respectively, Nov. 6, Dec. i, Jan. 2, 4, and 6, and are 

 very uniform in coloration. The November specimen is in 

 shorter and more worn pelage than the others, and for this rea- 

 son is perhaps a shade darker. Mr. Keays refers to this as the 

 " most common mammal of the region." 



Oryzomys keaysi is of about the size of O. prcetor Thomas, but 

 appears to have a relatively longer tail, and differs from that 

 species radically in coloration. It appears to have no very near 

 known ally. 



12. Oryzomys obtusirostris, sp. nov. 



Type, No. 15811, ? ad., Juliaca, Peru, altitude 6000 ft., Dec. 6, 1899 ; coll. 

 H. H. Keays. 



General color above blackish brown with a faint yellowish wash, giving a 

 slight general olivaceous effect, most pronounced on the sides, due to a slight 

 fulvous tipping of most of the hairs ; below dull buffy plumbeous, the huffy 

 tinge strongest on the breast ; ears black, well clothed with black hairs ; hind 

 November, igoo\ 15 



