588 PROCEEDINGS OF THE NATIONAL MUSEUM. tol. xxxi. 



white, with dark bases of hairs showing. Top of head, brownish 

 black, rather sparingly sprinkled with dirt}^ white. Inner side of 

 ears and small area in front of ear, cream-butf. Outer side of ear and 

 side of neck for about 10 mm. behind ear ochraceous-buff, devoid of 

 black grizzling. Fringe on outer surface of forearm, light tawny 

 ochraceous; outer side of foreleg a grizzle of dull black and dirty 

 white, dissimilar to sides of body; inner side of foreleg ochraceous- 

 buff, deeper than that of Ridgway ; lower foreleg and foot generally 

 buffy. Hind feet, light, ochraceous-buff; inside of hind leg and thigh 

 light ochraceous-buff, the longer hairs bordering the inner side tawny 

 ochraceous. Outer surface of hind leg almost as far as heel similar 

 to sides of body. Upper surface of tail dark brown, something 

 between Ridgway 's burnt umber and seal brown; underside of tail, 

 blackish for the outer half or two-thirds of the hairs; inner half of 

 hairs between buff and ochraceous-buff', the short, median appressed 

 hairs ochraceous. 



Skull and teeth. — In the great majority of cases RatiifajyoUa hancana 

 can be readily separated from Ratufa polla b}' the distinctly shorter 

 length of its tooth row and smaller teeth; but a few of the skulls in 

 the two series can not be so distinguished. 



Measurements. — Type: Head and body, 3i5 mm. ; tail vertebrse, 425; 

 hind foot, 76 (71). Skull of tj'pe: Upper length, 64.5; basal length, 

 54.0; basilar length, 50.9; cond^^lo-basal length, 58.7; palatal length, 

 28.7; zygomatic breadth. 39.5; interorbital constriction, 26.8; con- 

 striction behind postorbital processes, 21.6; diastema, 15.6; maxillary 

 tooth row (alveoli), 12.1; mandible, back of condj^Ie to front of sym- 

 physis, 40.4; mandibular tooth row, 13. For measurements of the 

 series see table, page 589. 



Specim£ns examined. — Fourteen; see table, page 589. 



Remarks. — Most of the specimens of Ratufa polla har^cana are in 

 old worn and bleached pelage, so that, in comparing the ser' s as a 

 whole with that of Ratufa jwlia., the two look very different. But by 

 comparing individuals in like stages of wear the differences, while 

 apparent and constant, are not so great. In the Banka animal the fore 

 and hind feet are lighter than they are in the Billiton one; the cheeks 

 and sides of the neck are lighter; the forearm and anterior shoulder 

 area are dirt}^ white grizzled with blackish, instead of ochraceous with 

 black grizzling. In the Banka form the heads are less gra}" than in 

 the typical form, but, as in the Billiton animal, the amount of light 

 coloring is somewhat variable. Some of the specimens show the 

 indistinct rings on the tails, such as are seen in R. polla. 



