Although described one hundred and thirty years ago, Vespertilio brachypterus Temminck remains a relatively poorly known species, such references as there are deriving for the most part from the original description or from specimens referred to V. brachypterus without direct comparison with the holotype. Described from Sumatra, the species was subsequently reported from Java by Fitzinger (1861:390) from the collection made during the exploratory voyage of the Austrian frigate "Novara", a report later repeated by Zelebor (1869: 17). Fitzinger (1870:24) gave a further description, as did Dobson (1876:92, 1878:223), who extended the range of the species to the island of Banka, apparently without reference to a specimen or published record. There have been few further references to the species other than those including it in faunal lists or similar accounts. Sody (1929a : 58) included it in the Javan list with some reservation and later (1937 : 227) questioned its reported occurrence on Banka. Chasen (1940 : 50) listed it from Sumatra, Java and questionably from Banka, referring (p. 50, footnote) a Javan specimen in the Bartels collection to V. brachypterus without direct comparison. Tate (1942:253) based a brief description on a "co-type" in the Rijksmuseum van Natuurlijke Historie, Leiden, putting V. brachypterus into his joffrei group of Pipistrellus with P. joffrei, P. stenopterus (both formerly referred to Nyctalus) and P. anthonyi. In a recent study of the genus Ρhiletor, Hill (1966: 386) suggested that from Tate and from the earlier description of a specimen in the Zoologisches Museum, Berlin by Dobson (1876:92, 1878:223) it seemed possible that V. brachypterus and P. stenopterus might be conspecific or consubspecific. Through the courtesy of the authorities of the Rijksmuseum van Natuur-