April, 1914. Four New Mammals from Venezuela — Osgood. 141 



Proechimys poliopus sp. nov. 



Type from San Juan de Colon, State of Tachira, Venezuela. Altitude 

 2,500 ft. No. 20525 Field Museum of Natural History. Subadult. 

 Collected Nov. 15, 1913, by M. P. Anderson. Orig. No. 160. 



Characters. — A relatively small species with grayish throat, fore- 

 arms, and fore and hind feet. Size about as in P. urichi and P. ochra- 

 ceus; smaller than P. mincce and P. guaircB; spines rather weak, about 

 as in P. urichi. 



Color. — Upper parts dull tawny liberally mixed with black on the 

 head and back, the sides being paler; under parts chiefly white, the 

 middle throat and an irregular line on each side of the belly drab gray 

 only slightly paler than the basal color of the hairs of the sides; front of 

 forearms and forefeet darker drab gray approaching broccoli brown; 

 hind feet grayish drab with a slight touch of whitish on the inner sides; 

 tail very lightly haired, blackish above, yellowish white below. 



Skull. — Similar to that of P. ochraceus but audital bullae decidedly 

 smaller, almost as small as in P. urichi; palatine foramina rather short 

 and broad leading posteriorly into shallow channels on each side of the 

 palate; zygomata somewhat heavier than in P. urichi and nasals shorter; 

 supraorbital ridges relatively weak; parieto-interparietal suture prac- 

 tically obliterated before full maturity; parietals without ridges; teeth 

 about as in P. ochraceus, slightly larger than in P. urichi. 



Measurements. — Type: Total length 363; head and body 223; tail 

 140; hind foot 46. Skull of type (last molar in place, but not quite 

 high enough to be functional): Greatest length 48.9; basilar length 

 34.4; zygomatic breadth 24.7; interorbital breadth 11. i; nasals 16. 6x 

 5.1; diastema 10; postpalatal length 18.3; palatine foramina 4.2x3; 

 upper toothrow 8.7. 



Remarks. — The gray forelimbs and feet distinguish this species from 

 all of its congeners to which it is similar in other respects. From P. 

 canicolUs, which also has gray limbs, it is distinguished by its smaller 

 size, its much darker and more uniform color (that of the head un- 

 differentiated from that of the body), and its cranial characters. P. 

 mincce sometimes has grayish forelimbs, but it is a larger species with 

 wholly white under parts. Actual comparison has been made with 

 topotypical material representing P. urichi, P. ochraceus, P. mincce, 

 and P. canicolUs. P. guairce is doubtless related also, but its larger size 

 and white feet distinguish it. 



