An aberrant specimen of the genus Laomedia De Haan, 1841, with an additional description of Laomedia astacina De Haan, 1841 and a new genus, Heteroaxianassa (Decapoda, Thalassinidea $^1$ , Laomediidae)

The genus Laomedia De Haan, 1841 of the family Laomediidae Borradaile, 1903 includes four known species, L. astacina De Haan, 1841, L. healyi Yaldwyn & Wear, 1970, L. paucispinosa Ngoc-Ho, 1997, and L. barronensis Ngoc-Ho & Yaldwyn, 1997. Herein, a fifth, possibly new species is described that, because of the lack of undamaged, adult specimens and the absence of locality data, is designated provisionally as Laomedia sp. A. Furthermore, an extended description of Laomedia astacina is provided, based on new material from Japan and also a newly revised key to the species of the genus Laomedia is presented. In addition, a new genus, Heteroaxianassa gen. nov., is proposed.