Report on the Haleciidae and Plumularioidea (Cnidaria, Hydrozoa) collected by the French SEAMOUNT 1 expedition

The study of a part of the material collected by the French oceanographic expedition "SEAMOUNT 1" made it possible to identify 21 species and one subspecies of hydroids of the families Haleciidae (4 species), Aglaopheniidae (7 species), Halopterididae (3 species), Kirchenpaueriidae (2 species and one subspecies) and Plumulariidae (5 species). Of these species, 10 have an Atlantic-Mediterranean distribution, 6 are cosmopolites, 4 are known from the north-eastern Atlantic, near to the area studied, and only one, Pseudoplumaria sabinae Ramil & Vervoort, 1992, is momentarily only known from Gorringe and Ampere Banks.