444 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxii. 



below are colored as they are above, the basal portion of the hairs 

 is light buffy and the middle portion ochraceous buffy. The short 

 appressed hairs underneath are mummy brown, with some ochrace- 

 ous buff hairs intermingled. Sides of head, white or buffy; cheeks 

 and nose, ochraceous buff, with some dark brown grizzling. Thig i 

 spot, buffy. 



Skull and teeth. — These show no special characters, except for their 

 smaller size. 



Measurements. — See page 445. 



Specimens examined. — Three from Indragiri River; five from Kate- 

 man River. 



Remarks. — From its geographical position, Ratufa catemana is 

 naturally associated with R. Tiypoleuca and R. arusinus, but its 

 resemblance in point of size and coloration to R. affinis of Singapore 

 and the Malay Peninsula is very striking. It differs from R. affinis 

 principally in having much darker upper parts, more white about the 

 head, and in having the feet concolor with the legs. Mr. Miller, in his 

 paper on Doctor Abbott's Indragiri River collection, pointed out that 

 this giant squirrel might be different from Ratufa hypoleuca of the 

 west coast. The Sumatran giant squirrels of the hypoleuca group 

 show in differentiation a striking analogy to the squirrels of the 

 Sciurus vittatus group,** in which the form inhabiting the lowlands of 

 south-eastern Sumatra is indistinguishable from that on the Malay 

 Peninsula; in which specimens from northern Sumatra differ from 

 those taken elsewhere on the island and in which the Tarussan Bay 

 form differs from east coast varieties. Whether the tliree forms of 

 the Tiypoleuca group are subspecies of one species it is impossible 

 to say. The material at present shows them to be very different, so 

 that no specimen in any one of the three series can be mistaken for 

 any specimen m. another of the series. 



oSee Lyon, Smithsonian Miscell. Coll., XLVIII, p. 277, Feb. 4, 1907. 



