The genus Laomedia De Haan, 1841 with description of a new species from Vietnam (Crustacea, Thalassinidea, Laomediidae)

To the genus Laomedia De Haan, a fourth living species from Vietnam, Laomedia paucispinosa n.sp., is added. New material of Laomedia astacina De Haan, 1841, from China, Japan, Taiwan, Vietnam, the holotype of Laomedia barronensis Ngoc-Ho et Yaldwyn, 1997, and a paratype of Laomedia healyi Yaldwyn et Wear, 1970, both from Australia, have been examined. Diagnoses of the genus and of each extant species are given, together with their descriptions and a key. Laomedia adults and larvae are compared to those of the other genera of the Laomediidae, and on the basis of a phylogenetic analysis using seventeen characters, two subfamilies, Laomeniinae and Axianassinae, are recognized.