Descriptions of two estuarine species of Haplostylus (Crustacea, Mysidacea)

Haplostylus udrescui sp. nov. from Australia is described, a redescription of the male of Haplostylus queenslandensis Bacescu and Udrescu (1982) is given and the female recorded for the first time. A comparison of the eight species of Haplostylus known from eastern Australia shows that H udrescui differs from all others by the combination of the following characters presence of carapace lappets, exopod of uropod longer than endopod; weakly developed rostrum; proximity and similar size of the posterior two telson spines.