224 Mammals of Eastern Asia 
Cockerell's Tree Squirrel, Callosciurus cockerelli, is a small 
species with bright red back, gray sides, and white underparts. 
The edges of the ears are white, the limbs and feet grizzled 
gray. The basal part of the tail is mixed red and white, the ter- 
minal half almost completely white. The length of the head and 
body is 8 1 /! inches, of the tail 8% inches, hind foot slightly less 
than 2 inches. This Tree Squirrel is known only from northern 
Siam. 
The Siamese White Tree Squirrel, Callosciurus finlaysoni, 
has the fur nearly white with gray bases, the tail also white, with 
a few black hairs added. The length of the head and body is 
about 8% inches, of the tail 8% inches, of the foot just under 2 
inches. Although the form originally described from Siam was 
white, this Squirrel is known to be almost as variable as C. slo- 
deni. Specimens are often taken that have patches of red on the 
white, or even have red predominating and the white reduced to 
a few spots. Osgood records the species from Kratie, Cambodia. 
White examples of this Squirrel are remarkably similar to 
C. sladeni haringtoni of Burma. 
The Siamese Black Tree Squirrel, Callosciurus bocourtii, 
has the hairs of the body and limbs black, tipped with red, and 
the underparts and inner sides of the limbs yellowish white. The 
head is reddish brown, the ears brown with a few white hairs, 
the face, cheeks, and throat whitish. The tail basally is colored 
like the body but terminally is strongly reddish, and beneath 
somewhat yellow. The head and body, and the tail each measure 
about 11 inches (Milne- Edwards). This Squirrel is found in the 
neighborhood of Ayutha, Siam. Other races are C. b. sinistralis 
of central Siam, C. b. dextralis of the lower Me-Ping Valley, 
Siam, C. b. grutei and C. b. lylei both of northern Siam, and 
C. b. floweri of Bangkok. 
The Siamese Black-backed Tree Squirrel, Callosciurus 
atridorsalis, is generally colored a shade of gray, composed of 
buff and black, which becomes whitish on the limbs. The middle 
