Knowledge of the avifauna of Formosa or Taiwan has been summarised excellently by Hachisuka & Udagawa (1950, 1951), who included references to many publications by Japanese authors, not readily available in Europe. As far as published evidence goes, not much ornithological work has been done in Formosa since 1951 : I have found only a few more recent papers, each dealing with a single species (Deignan, 1958, 1964; Ripley, 1962; Wayre, 1968). Barnes & McLure (1966) recorded that bird-ringing has begun on the island. Over the past few years (1967-1969) the Rijksmuseum van Natuurlijke Historie has acquired from Mr. K. H. Chen of Taipei a large collection of Formosan birds. Whereas, obviously, the majority belong to species well known from Formosa, two species, both migrants, are new to the island, and several others have rarely been recorded or are little known. In this paper only the rare, or for some other reason interesting, species are discussed. As a by-product of the work on Formosan birds, a first record of Gallinago stenura from the Moluccas came to light, and some revisional notes on Halcyon coromanda are given, with a description of a new race from the Soela Islands. For the loan of material of Accipiter virgatus and Porzana fusca I am under obligation to authorities of the British Museum (Natural History), United States National Museum, American Museum of Natural History, and Field Museum, Chicago. In discussions and lists of material, these names have been abbreviated to BM, USNM, AMNH, and FM. Accipiter soloënsis (Horsfield)