Nine specimens, three from Sirhassen Island and six from Pulo Subi.
Those from Pulo Subi, while agreeing with the topotypes in color, appear to average a trifle smaller, though the series is hardly extensive enough to prove that this is constant.
RATUFA SIRHASSENENSIS (Bonhote).
1894. Sciurus bicolor albiceps Thomas and Hartert, Novitates Zoologicæ, I, p. 659. September, 1894 (Sirhassen).
1900. Ratufa ephippium sirhassenensis Bonhote, Ann. and Mag. Nat. Hist., 7th ser., V, p. 498. June, 1900 (Sirhassen).
Two specimens, Sirhassen, June 8, 1900.
This species, though related to Ratufa ephippium, with which it agrees in color-scheme, is sharply differentiated by its small size and cranial peculiarities. It is in no way closely allied to Ratufa bunguranensis and R. nanogigas.
As compared with that of Ratufa ephippium sandakanensis Bonhote, the skull in addition to its small size (greatest length 57 instead of 65) differs in general narrowness, in the relatively greater breadth of the nasal branches of the premaxillaries, and in the form of the audital bullæ. When the skull is held upside down and viewed from behind the bullæ are seen to be narrower than in the Bornean animal and to rise to a much greater height above the surface of the basi-occipital.
RATUFA BUNGURANENSIS (Thomas and Hartert).
1894. Sciurus bicolor bunguranensis Thomas and Hartert, Novitates Zoologicæ, I, p. 658. September, 1894 (Bunguran).
1895. Sciurus bicolor bunguranensis Thomas and Hartert, Novitates Zoologicæ, II, p. 491. December, 1895 (Bunguran).
1900. Ratufa ephippium bunguranensis Bonhote, Ann. and Mag. Nat. Hist., 7th ser., V, p. 497. June, 1900.
Thirteen specimens from Bunguran, all in various stages of the change from the bleached winter coat to the summer pelage. In the latter there is some color variation, mostly due to the greater or less distinctness of the drab wash overlying the Prouts-brown or 'chocolate' 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 affinis, though less conspicuous.