Three new genera and five new species of misophrioid copepods (Crustacea) from anchialine caves on Indo-West Pacific and North Atlantic Islands

Hydra lirosoma sp. nov. is a small, hermaphroditic species possessing broad holotrichous isorhiza nematocysts. The spherical embryo and cobbled embryotheca set it apart from similar species. Hydras with broad holotrichous isorhizas form a distinct cluster of species, but one which was not explicitly represented in the three genera ( Pelmatohydra, Hydra and Chlorohydra ) recognized by Schulze (1917, Archiv für Biontologie, 4(2 ): 29). Schulze failed to recognize this group because of the small number of species known at that time. The hydras that are known now fit naturally into four clusters of species termed, in this paper, the oligactis, vulgaris, viridissima, and braueri groups.