H 
401 4 
t 
On a new Agouti from British Guiana. 259 
Ke yf XXVII.—A new Agouti from the Moon Mountains, Southern 
\4" 
British Guiana, with Notes on other Species. By Oup- 
FIELD THOMAS. 
(Published by permission of the Trustees of the British Museum.) 
THE agouti of the Moon Mountains, Southern British Guiana, 
seems to represent a new subspecies of D. agut’, L., a name 
under which I propose to place all the orange-rumped agoutis 
with the exception of the small insular LV. rubrata of 
Trinidad. . 
The members of this group from the coast-region of 
North-eastern Venezuela and Northern Guiana are probably 
all referable to a single form, ranging from Cumana to 
Cayenne. The earliest name for them is D. a. flavescens, 
Lhos., the later names lucifer and cayenne being probably 
due to the great variation which our now considerable 
series from Demerara shows the animal to be liable to. 
Normal specimens from this area are dark-coloured, with 
blatkish nape and darkened withers, the yellowish of the 
rump dark fulvous, and the under surface brown, with but 
little mesial lightening ; the feet usually black. In individual 
specimens, however, all parts, and especially the rump, may 
be very much lighter. 
In Brazil, on the other hand, the true D. aguti is always 
much lighter, the nape and withers without blackening, the 
under surface with a broad and distinct mesial line of white 
or yellow running its whole length from chest to inguinal 
region, the feet more or less grizzled with orange. 
But from the Moon Mountains a series of specimens differ 
from both, and may be described as 
Dasyprocta aguti lunaris, subsp. n. 
Nape and fore back grizzled olivaceous grey, without any 
blackening. Rump ochraceous orange, generally darkened 
by inconspicuous blackish subterminal bands on the hairs— 
the colour fairly uniform.in the series available. Flanks, 
sides of rump, and legs grizzled olivaceous, the orange not 
extending downwards on to them. Under surface scarcely 
lighter than sides, without median light stripe on chest, 
. though there is generally an irregular whitish lightening on 
the belly and inguinal region. Hands brown, blackish, or 
grizzled. Feet grizzled oliyaceous, only darkening to 
blackish terminally. 
