A revision of the genus Halectinosoma (Copepoda : Harpacticoida : Ectinosomatidae): the H. herdmani (Scott & Scott) group of species

Ectinosomatid material was examined from extensive collections around the B ritish Isles and from several additional world localities and museum collec tions, permitting a revision of the genus Halectinosoma. This paper redescr ibes H. herdmani and describes five new species: H. bodotriaensis sp. nov., H. pilosum sp. nov.? H. britannicum sp. nov.? H. itoi sp. nov. and H. huys i sp. nov, These species, together with H. tenerum (Sars) and H. kunzi Lang , are referred to the 'herdmani species group', on the basis of close simil arity. H, herdelongata (Marcus) is synonymized with H. herdmani H. elongatu m (Sars), previously regarded as incertae sedis, is also redescribed. Despi te a superficial resemblance to the herdmani group of species, H. elongatum was found to be morphologically quite distinct. H. intermedium (Nicholls) was found to be a synonym of H. elongatum. The species H. finmarchicum (T. Scott) is discarded; the original description was found to be based largely on material of H. elongatum but mistakenly included the female fifth leg f rom H, angulifrons (Sars). A key for the identification of females of the h erdmani group of species is provided. (C) 2000 The Linnean Society of Londo n.