130 MILLER 



change from the bleached winter coat to the summer pelage. In the 

 latter there is some color variation, mostly due to the gi'eater or less 

 distinctness of the drab wash overlying the Prouts-brown or ' choco- 

 late' of the upper parts. Not only does the drab vary in amount in 

 different individuals, but on every specimen it is more noticeable when 

 the animal is viewed from in front. The drab wash is of the same 

 character as that in Ratufa ajffinis^ though less conspicuous. 



As Mr. Thomas has pointed out to me, after examining a specimen 

 of the latter, Ratufa bungiwanensis is closely allied to R. pyrsonota. 

 Indeed its relationship to the Siamese species is much closer than to 

 the R. epkt'ppzum of Borneo. Together with R. pyrsonota the Bun- 

 guran giant squirrel differs conspicuously from that of Borneo in its 

 narrow skull, lengthened audital bullce, dark feet, dark median line on 

 under surface of tail, and entirely brown back. From R. pyrsonota, 

 however, it is readily separable by its darker, less ochraceous color 

 both above and below, drab washed back, and by the much less dis- 

 tinct annulation of the hairs of the dorsal surface. 



RATUFA NANOGIGAS (Thomas and Hartert). 



1895. Sciurus bicolor nanogigas Thomas and Hartert, Novitates Zoologicae, 



II, p. 491. December, 1895 (Pulo Laut). 

 1900. Ratufa ephippiuni fianogigas Bonhote, Ann. and Mag. Nat. Hist., 



7th ser., V, p. 498. June, 1900 (Pulo Laut). 



Four specimens, all from Pulo Laut, the type locality. 



This strongly characterized dwarf species is allied to Ratufa Pyr- 

 sonota and R. bunguranensis with which it agrees in color scheme. 

 It is in no way closely related to the large Bornean R. ephif>pium. 



RATUFA ANGUSTICEPS sp. nov. 



lype. — Adult male (skin and skull) No. 104646 U. S. National 

 Museum. Collected on Pulo Lingung, off south coast of Bunguran, 

 June 17, 1900. Original number 481. 



Characters. — Externally like Ratufa a?zambce and R. ?nelanopepla. 

 Skull about equal to that of latter in length, but conspicuously narrower. 



Color. — As the color is precisely like that of Rattfa ana7nbcB and 

 R. melanopepla it requires no description. 



Skull and teeth. — The skull is immediately recognizable by its gen- 

 eral narrowness, but particularly in the region of the anterior zygomatic 

 roots. Ratio of lachrymal breadth to greatest length, 39. In the other 

 black backed species it is about 42. Audital bulls narrower and 

 more elongate than in R. melanopepla., and more elevated above level 

 of basi-dccipital (when skull is held upside down). Lateral processes 

 of basi-occipital obsolete. 



