138 On Giant Squirrels from the Amazonian Region. 



enabled me to fix 8. tricolor as one of the two species found 

 by Mr. Goodfellow on the Coca. Its differences from its 

 ally are enumerated below. The type is an old female, and 

 though it was said by Prof. Gravenhorst * to have only 

 6 mamma}, careful search shows that it has 8, the usual 

 number in this group. 



The skull of 8. tricolor is less bowed than in the other 

 species and has an unusually long narrow muzzle. 



The melanoid S. fumigatus, Gray, from the " Upper 

 Amazon," may possibly be referable to S. tricolor, but its 

 determination must always remain somewhat doubtful. The 

 same author's 8. hrunneoniger is also a member of the present 

 group, but is not like any properly localized specimen that I 

 have seen. 



Sciurus cocalis, sp. n. 



Not dissimilar at first sight to S. tricolor, found in the same 

 place, and it is only after the examination of three skins of 

 one form and seven of the other that I have satisfied myself 

 of their essential difference. General colour above grizzled 

 yellowish anteriorly, becoming chestnut-rufous posteriorly. 

 Crown finely grizzled rufous, not blackish. Backs of ears 

 rich rufous, a prominent spot behind their posterior bases 

 bright fulvous. Under surface clear buffy or orange- buffy, 

 becoming more rufous on the throat and inner sides of the 

 limbs; line of demarcation on sides sharply defined and in 

 most specimens with a distinct black line running along the 

 lower edge of the upper colour, and an indication of a rufous 

 line along the pale colour just below it. Fore limbs bright 

 orange-rufous on their outer surfaces from the elbows down- 

 wards. Hind limbs chestnut-rufous externally as far down 

 as the ankles, then the feet are again orange-rufous like the 

 fore limbs. Tail long, bushy, black for its basal 3 inches, 

 then broadly washed with bright orange-rufous, and so far 

 like that of S. tricolor, but below the black which succeeds the 

 rufous on the hairs there is a broad band of yellowish or 

 orange, which may either extend downwards to the bases of 

 the hairs or be succeeded again by another dull ring. 



Skull shorter, more bowed, and with a more normal-shaped 

 muzzle than in 8. tricolor. 



Dimensions of the type (an adult male, measured in 

 skin) : — 



Head and body 315 millim.; tail 283, with terminal 

 hairs 345 ; hind foot (wet), s. u. 63, c. u. 66 ; ear (wet) 32. 



* Tschudi, Faun. Peruana, Mamm. p. 157 (184o). 



