Cranial measurements of type: greatest length 12.4 (12);[26] basal length 11.8 (11.6); basilar length 9 (9); zygomatic breadth 8.4 (8); least interorbital breadth 3.2 (3.2); greatest length of braincase 8 (7.6); greatest breadth of braincase above roots of zygomata 6.6 (6.6); mandible 8.8 (8.4); maxillary toothrow (exclusive of incisors) 4.2 (4.2); mandibular toothrow (exclusive of incisors) 4.8 (4.8). _Specimens examined._--Six (in alcohol), all from the type locality. _Remarks._--I am unable to identify this bat with any described species. Externally it is practically identical with _Pipistrellus pipistrellus_ except that the color, so far as can be judged from specimens preserved in alcohol, is more blackish. Internally it is readily distinguished by the characters of the skull and teeth. From _Pipistrellus abramus_ it differs externally in smaller size, narrower ears, and in the absence of any unusual development of the penis. The incisors differ from those of _P. abramus_ in the same manner as from those of _P. pipistrellus_. HIPPOSIDEROS LARVATUS (Horsfield). Two specimens (one in alcohol) were collected on Sirhassen Island, June 6 and 7, 1900. RHINOLOPHUS AFFINIS (Horsfield). One badly damaged specimen from Bunguran appears to be referable to typical _Rhinolophus affinis_. The forearm cannot be measured, but the third finger is 75 mm. in length. Tibia 21, foot 10.4, ear from meatus 21. Ridge on muzzle beneath edge of nose leaf low, broad and hairy, not in the least suggesting a supplementary leaflet. RHINOLOPHUS SPADIX sp. nov. 1894. _Rhinolophus affinis_ THOMAS and HARTERT, Novitates Zoologicæ, II, p. 656. December, 1895 (Sirhassen). _Type._--Adult female (in alcohol) No. 104752 U. S. National Museum. Collected on Sirhassen Island, South Natunas, June, 1900. _Characters._--In general like _Rhinolophus affinis_ but much smaller. Color uniform tawny brown. Muzzle with distinct supplemental leaflets. _Muzzle._--Muzzle and noseleaf precisely as in _Rhinolophus affinis_, except that the ridge on muzzle beneath edge of horseshoe is developed into a distinct supplemental leaflet resembling those present in _Hipposideros_. In this respect _Rhinolophus spadix_ resembles the animal from Burmah referred by Thomas to _Rhinolophus rouxii_;[27] but the terminal erect portion of the noseleaf is not shortened or in any way peculiar in form. _Ears._--The ears resemble those of _Rhinolophus affinis_, except that they are not as large. _Color._--Fur everywhere russet, slightly paler on ventral surface, darker and somewhat tinged with hazel above. Ears and membranes dark brown. _Skull and teeth._--The skull and teeth exactly resemble those of mainland specimens of _Rhinolophus affinis_ except for their uniformly smaller size.