; 
Oct., 1915. MAMMALS FROM BRAzIL AND Peru — Oscoop. 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,f 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. 
