7 
SCIURIDM—SCIURUS LEUCOPS. TO 
Lichtenstein’s MS. name hypoxanthus has of course priority over both, 
but seems not to have been published except through this incidental refer- 
ence to it by Geoffroy; and indeed there is no proof that the specimens so 
named were not referable to the true aureogaster of F. Cuvier. 
Dr. Gray’s M. griseoflavus and M. leucops are both described on the 
same page; and, although griseoflavus stands first, I adopt the name deucops as 
agreeing better with the specimens figured and described by Geoffroy, while 
they come also from substantially the same locality; but I at the same time 
believe griseoflavus to be specifically the same, notwithstanding the more 
uniform coloration of the dorsal surface. 
A comparison of Geoffroy’s description and figures with those given by 
Cuyier shows at once the wide differences between them, which Geoffroy 
himself thus notices:—“ En comparant cette description 4 celle de M. 
Frédéric Cuvier ou & Pun des individus qui nous sont venus en 1829 et en 
1831 de la Californie et du Mexique, on reconnaitra immédiatement de nom- 
breuses et remarquables analogies avec ceux-ci, mais aussi de notables diffé- 
rences. L’Ecureuil de la Vénus,en méme temps qu’il manque inférieurement 
dela couleur rousse qui serait caractéristique pour l’espéce selon les auteurs, . 
plus de roux sur les parties supérieures; et cela, non-seulement sur la croupe 
et la nuque ott le roux domine, mais méme sur le dos, ot les poils ont une zone 
rousse dont d’autres individus ont X peine un vestige. L’Ecureuil de la Venus 
ne devrait-il done pas étre considéré comme une espéce voisine, mais dis- 
tincte du Sciurus aureogaster ou hypoxanthus?” Ue refers to the wide range 
of individual variation presented by several well-known species, and is influ- 
enced by this in referring the specimens collected by the Vénus to Cuvier’s 
S. aureogaster. é 
In size and proportions, there is little difference between the present 
species and S. aureogaster, but the difference in coloration is so pronounced 
and of such a character as to leave little doubt of their distinctness. In S. 
aureogaster, the hairs of the dorsal surface have, in some specimens, a pale 
central narrow ring of rust, but often the hairs are wholly black beneath the 
surface and merely narrowly tipped with white. None of the sixteen speci- 
mens of S. aureogaster before me show any approach to any of the six 
specimens of S. deucops, yet more abundant material may show that they are 
not specifically separable. Among the specimens from Tehuantepec are 
typical representatives of both forms. 
