Cranial measurements of type: greatest length 102 (115);[23] basal length 96 (106); basilar length 92 (103); median palatal length 53 (60); palatal breadth between anterior molars 13 (15.4); zygomatic breadth 55 (60); breadth between tips of postorbital processes 41 (39); constriction in front of postorbital processes 19 (18); constriction behind postorbital processes 13 (12); breadth of braincase above roots of zygomata 32 (33); mastoid breadth 36 (38); mandible 76 (86); maxillary toothrow (exclusive of incisors) 34[24] (41); mandibular toothrow (exclusive of incisors) 39 (44); crown of first upper molar 5.4 × 5 (5.4 × 5.6); crown of second upper molar 4 × 5 (5.4 × 6.4); crown of second lower molar 7 × 4.2 (8.4 × 5.4). _Specimens examined._--Seven (two young in alcohol and one skull without skin), all from the type locality. _Remarks._--_Arctogalidia inornata_ is so distinct from the previously described species as to require no special comparisons. It is common on Bunguran where it frequents the cocoanut trees, living for the most part in the tops among the leaf stalks. VIVERRA TANGALUNGA Gray. 1895. _Viverra tangalunga_ THOMAS and HARTERT, Novitates Zoologicæ, II, p. 490. December, 1895 (Bunguran). Nine specimens from Bunguran. These agree in all respects with the Bornean animal. TUPAIA SPLENDIDULA Gray. 1894. _Tupaia splendidula_ THOMAS and HARTERT, Novitates Zoologicæ, I, p. 656. September, 1894 (Bunguran). 1893. _Tupaia splendidula typica_ THOMAS and HARTERT, Novitates Zoologicæ, II, p. 489. December, 1895 (Bunguran). Two specimens from Bunguran. TUPAIA LUCIDA (Thomas and Hartert). 1895. _Tupaia splendidula lucida_ THOMAS and HARTERT, Novitates Zoologicæ, II, p. 490. December, 1895 (Pulo Laut). Seven specimens (two in alcohol) from Pulo Laut. TUPAIA SIRHASSENENSIS sp. nov. 1894. _Tupaia tana_ THOMAS and HARTERT, Novitates Zoologicæ, I, p. 657. September, 1894 (Sirhassen). _Type._--Adult male (skin and skull) No. 104712 U. S. National Museum. Collected on Sirhassen Island, South Natunas, June 5, 1900. Original number 442. _Characters._--In general similar to Bornean specimens of _Tupaia tana_, but smaller (hind foot 47 instead of 52, greatest length of skull 55 instead of 60), gray markings on head and shoulders less distinct, and red of tail brighter. Rostral portion of skull less attenuate than in _Tupaia tana_. _Color._--The color so exactly resembles that of the common Bornean _Tupaia tana_ as to need no detailed description. Gray of head darker than in the Bornean animal and light shoulder markings less distinct and sharply defined. Under side of tail light orange-rufous, darkening to ferruginous toward edge. (In _T. tana_ these colors are replaced by dull ferruginous and hazel respectively.)