The male and female type material of Haemaphysalis (Allophysalis) warburtoni Nuttall, from a serow in Szechwan, China, is redescribed and males of this species are reported from a Himalayan thar in Uttar Pradesh, India. Both hosts are mountain-inhabiting members of the Order Artiodactyla (Bovidae, Caprinae). The single specimen reported as H. warburtoni from Formosa (Taiwan) is found to represent H. (H.) formosensis Neumann. The hosts, biology, life cycle, and disease relationships of H. (A.) warburtoni have been the subject of numerous Soviet reports; many (if not all) of these refer actually to H. (A.) pospelovashtromae sp. n., which is described from males, females, nymphs, and larvae. Adults of the newly recognized species parasitize cattle and domestic and wild goats in the mountains of southern RSFSR and southern republics of USSR. Haemaphysalis warburtoni Nuttall (1912) was sketchily described and illustrated from a single collection removed in England from a serow or goat antelope originating in Szechwan, China. No other samples are known from China. Over the years, a number of papers concerning scattered, high-altitude populations of ticks attributed to H. warburtoni from Mongolia, RSFSR, and southern republics of the USSR have provided a rather large amount of interesting information on hosts, life cycle, ecology, and disease relationships of this taxon. From published information, it has appeared that H. warburtoni is a uniform species with an extensive, discontinuous, relict-type distribution pattern ranging from Taiwan, China, and Mongolia in the east to Georgia SSR in the southwest. Recently we have been fortunate to be able to study the type material of H. warburtoni in the British Museum (Natural History), the single specimen attributed to this species from Taiwan, one collection from the Himalayas, and several excellent samples from USSR. It is now apparent that the specimen reported Received for publication 14 March 1966. *From Research Project MR005.09-1402.3, Bureau of Medicine and Surgery, Department of the Navy, Washington, D. C. The opinions and assertions contained herein are the private ones of the author and are not to be construed as official or as reflecting the views of the Department of the Navy or of the naval service at large. from Taiwan was misidentified and that all available samples from USSR differ from the Chinese type material of H. warburtoni in a number of critical features. Lack of immature stage samples of certain species and convergent adaptation among adults of structurally primitive species that have evolved from different branches more or less closely related to H. warburtoni cause confusing systematic problems at the subgeneric level, which is intended to express phylogenetic relationships. These are discussed below. Haemaphysalis (Allophysalis) warburtoni Nuttall Warburton's Chinese Serow Haemaphysalid