K0.1534. GIANT SQUIRRELS OF SUMATRA— LYON. 443 



margin and tip is the same, followed by an irregular line of the color 

 of the underparts of body, while centrally it is irregularly cream-buff; 

 the short-haired portion in the middle line is a mixture of ocliraceous 

 buff and blackish brown. In worn pelages the brown of the upper 

 parts of body becomes lighter and duller, and the grizzling is less con- 

 spicuous; the brown of the tail becomes much lighter. 



Sliull and teeth. — These show no special characters, and it is appar- 

 enth" impossible to distinguish skulls of Ratiifn arusinus from skulls 

 of R. hypoleuca. 



Measurements. — Ratufa arusinus closely agrees with R. hypoleuca 

 in size. See page 445. 



Specimens examined. — Thirteen from the vicinity of Aru Bay, 

 northeastern Sumatra. 



RemarTiS. — While clearly related to Ratufa hypoleuca, R. arusinus 

 possesses several well-marked characters, such as light upper parts, 

 dark buff underparts, brown feet, and less white about the head, by 

 which it may be differentiated from the former. At present it is 

 known only from the vicinity of Aru Bay. Possibly it may have a 

 distribution similar to that of Sciurus vittatus albescens and be found 

 to occur throughout the northern end of Sumatra. 



RATUFA CATEMANA, new species. 



1902. Ratufa hy2}okwaMiLi.ER, Proc. Acad. Nat. Sci. Phila., March, 1902, p. 149; 

 issued June 11, 1902. Indragiri River specimens. 



Type.— Adult male, skin and skull, Cat. No. 123124, U.S.N.M., col- 

 lected along the Kateman River, southeastern Sumatra, August 27, 

 1903, by Dr. W. L. Abbott. Original number, 2759. 



Diagnostic characters. — Similar to Ratufa hypoleuca, but much 

 smaller, upper parts lighter, under parts usually buff instead of white, 

 and wliite about head much less conspicuous. 



Color. — The colors of Ratufa catemana are rather difficult to de- 

 scribe. The specimens were collected in August and September and 

 appear to be in old and worn pelage, not comparable with the pelage 

 of the species described above. Top of head and neck, upper parts 

 and sides of body, and upper surface of tail have the general effect of 

 Ridgway's broccoli or wood brown. Where there is an indication of 

 fresh pelage, especiall}^ along the sides, the color seems to be similar 

 to that of Ratufa arusinus. The fore and hind feet and outer surfaces 

 of legs and sides of body bordering the light underparts are tawny, 

 with a slight amount of dark-brown grizzling on the feet and arms. 

 The underparts vary from whitish (especially in the Indragiri River 

 skins) to a dark buff or ocliraceous buff. The tail, above, is generally 

 a dull brown, similar to Ridgway's wood or broccoli brown. A 

 young example, Cat. No. 123125, U.S.N.M., shows indistinct annula- 

 tions on the tail. The outer edge and the tip of the tail seen from 



