OCT., 1915. MAMMALS FROM BRAZIL AND PERU OSGOOD. 193 



procta prymnolopha, but coloration differing in many respects, notably 

 in the banded instead of clear yellowish or rufescent hairs of the sides 

 of the rump. 



Color: Elongated hairs of nape and rump glossy black, the basal 

 half of the hairs dark quaker drab, in some cases with one or two bands 

 of pale buffy; hairs of top of head, face, sides of body, and proximal 

 part of legs sharply banded black and buffy or ochraceous, the light 

 bands paler and narrower anteriorly, especially on the sides of the 

 shoulders, lighter, more ochraceous, and broader posteriorly on the 

 sides of the rump; fore and hind legs mostly banded also, but narrowly; 

 inner side of hind legs with a narrow line nearly clear buff; maxillary 

 region and chin creamy buff; middle of throat with hairs broadly buff- 

 tipped and with dark drab bases; hairs of chest ochraceous without dark 

 bases, the same color extending along the abdomen on each side of a 

 narrow central line of white; sides of abdomen banded ochraceous and 

 drab; fore and hind feet black, finely sprinkled with ochraceous; front 

 and inner sides of ears thickly clothed with rich ferruginous hairs; a 

 thick tuft of bristly black hairs over each eye. 



Skull: Somewhat smaller and narrower than that of Dasyprocta 

 aguti; palate narrow; palatine foramina narrow and slitlike; jugal 

 relatively broad posteriorly but narrow anteriorly and without any 

 pronounced tendency to the development of an angle or postorbital 

 process; infraorbital opening of lacrymal canal at base of incisor narrow 

 and constricted in the middle, much smaller than in other species; 

 supraoccipital rather narrow; teeth about as in D. aguti. 



Measurements: Type, measured in the flesh by the collector: 

 Total length 511; hind foot 113. Skull of type: Greatest length 96.2; 

 basilar length 72.7; zygomatic breadth 43.9; least interorbital breadth 

 26.5; mastoid breadth 33.2; nasals 32.3X15.5; length of palate 35.8; 

 width of palate at middle of second molar 6.6; diastema 22.7; depth of 

 jugal in middle 4.5; upper toothrow * (alveoli) 18.2. 



Remarks: Of the described species of Dasyprocta, the only one 

 approaching this very distinct new form is Dasyprocta prymnolopha, 

 supposed to have come originally from Guiana. Although no speci- 

 mens of D. prymnolopha are at hand, descriptions of that species, of 

 which the best seems to'be that given by Waterhouse,t indicate that 

 there are many characters distinguishing it from the above described 

 form. In typical prymnolopha, as described, the black rump is bordered 

 on each side by clear golden or chestnut, the long rump hairs are yellow- 



* Milk premolar still present but permanent tooth in place and visible beneath it. 

 t Mamm. II, p. 380, 1848. 



