SCIURIDA—SCIURUS ASSTUANS AND VARIETIES. (Hs, 
the inner side of the limbs like the belly ; sometimes, however, the feet are 
colored like the belly, the color of the ventral surface also sometimes invad- 
ing the outer surface of the limbs. The sides of the face and chin vary from 
grayish-brown to deep yellow or orange. 
Specimens from Venezuela are smaller, and are undistinguishable from var. 
_estuans above, but still retain the bright-red edging of the tail, which is, how- 
ever, lighter or more golden than in Costa Rica specimens. This form appears 
to extend, with very slight modifications, southward through New Granada to 
Eastern Peru. 
GENERAL REMARKS UPON SCIURUS ASTUANS AND ITS VARIETIES. 
DIFFERENTIAL CHARACTERS.—The two varieties of Sciurus estuans differ 
in the larger size and more reddish coloration of the northern form, and 
especially in respect to the color of the tail. Var. rufoniger averages fully an 
inch longer than var. @stuans; the color is much more rufous, the tail broadly 
edged with red instead of narrowly edged with pale yellow, and the ventral 
surface is deep reddish-orange instead of reddish-yellow. In the tables of 
measurements, the tail appears to be relatively the shorter in var. rufoniger, 
but the difference is not real. In the case of var. @stuans, the measurements 
were taken from specimens preserved in alcohol, while the measurements of 
var. rufoniger were taken from skins, from the tails of which the vertebree 
had generally been removed, leaving merely the shrunken distorted skin. 
SYNONYMY AND NOMENCLATURE.—Linneus’s description of Sciurus @stu- 
ans was based on specimens from Surinam, and is the same animal as the S. 
brasiliensis of Maregrave and Brisson. The name @stuans is the one by which 
the Brazilian Squirrel has generally been recognized by authors. For a long 
time, the only prominent synonym was pusi/lus, a MS. name given by 
Geoffroy to young specimens from Cayenne, in the Paris Museum, which 
name appears to have been first published by Desmarest in 1817. This is 
also the origin of Buffon’s ‘Petit Guerlinguet”, and the Ecureuil nain of 
other French authors. For many years, these names all uniformly referred to 
the original example in the Paris Museum.* Gray, in 1867, referred to a 
second specimen, “four and a half inches long” (head and body), as being in 
the British Museum, from ‘Tropical America”. I have before me another, 
from Brazil, which I believe to be only a very young example of S. @stuans, 
*“Tl se trouve & Cayenne; c’est de 1a que Laborde envoya 4 Butfon le seul individu qui, jusqu’a 
présent, ait été décrit.”—(l°. Cuvimr, Dict. des Sciences Nat. tom. xiv, 1819, p. 248.) 
