THE NE ATLANTIC GLASS SPONGES PHERONEMA-CARPENTERI (THOMSON) AND PHERONEMA-GRAYI KENT (PORIFERA, HEXACTINELLIDA) ARE SYNONYMS

Since 1870, it has been generally accepted that two very similar speci es of the amphidiscophoran genus Pheronema Leidy inhabit the NE Atlant ic. Pheronema carpenteri (Thomson, 1869) was first described as the in dicative organism of the 'Holtenia ground' NW of Scotland at 970 m. Ph eronema grayi (Rent, 1870) was described from the coast of Portugal fr om similar depth. The species were differentiated mainly by body form and distribution of conspicuous external spiculation. Occurrences of t he two species reported since then document their broadly overlapping horizontal and vertical distributions at bathyal depths throughout the NE Atlantic and E Mediterranean. Conspicuously, not one of 16 collect ions containing either species included both species. Review of litera ture descriptions and inspection of key specimens show that no charact ers provide unambiguous differentiation of the two forms. Based upon t his evidence, and discovery of correspondence in which Kent privately negated the validity of his species, it is concluded that only one spe cies population of Pheronema occurs in this region. Pheronema grayi is thus a junior synonym of P. carpenteri. (C) 1995 The Linnean Society of London.