dehby’s opossum. 
493 
Section IT. Opossums in which the pouch is rudimentary , 
or entirely wanting. 
Didelphys affinis. 
Didelphys affinis. (Natterer) Wagner, in Wiegmann’s Archiv. fur 
Naturgesch. vol. viii. Pt. 6 for 1842, p. 358. 
General tint reddish ; under parts yellowish white ; tail longer 
than the body, spotted with white, both above and beneath ; 
pouch wanting. Length of head and body 9 iuches ; of 
tail, 10 inches. 
Inhabits Brazil (Matto grosso). 
DIDELPHYS DERBIANUS. 
Derby’s Opossum. 
Didelphys Derbiana. Waterhouse, Naturalist’s Library (Marsupialia), 
vol. xi. p. 97, PI. 2. Aug. 1841. 
Body stout; tail considerably longer than the head and body taken 
together, and covered with fur for more than one-third of its 
length; fur of moderate length ; general colour bright 
brownish rust; under parts dirty white; head greyish, and 
with a longitudinal dusky line above; lower half of fore legs 
white; hind feet dusky; naked portion of tail of a pale 
tint, but spotted with dark brown; a short silvery-grey stripe 
along the back. 
Inhabits-P 1 
In having a dark mark on the head, and the naked portion 
1 Dr. Schinz states that Dr. Tschudy, in a recently published account of 
Peru, has described a species of Opossum, under the name bicolor; the work 
in question has not yet found its way into our National Library, and I have 
not been able to procure it. 
