Revision of the genus Asconema (Porifera: Hexactinellida: Rossellidae)

Abstract
The genus Asconema, widely distributed in the North Atlantic and Arctic, was for some time considered to be monospecific. Its revision shows that it contains five species including the previously known A. setubalense, reinstated A. foliata and three new species (two of which are subdivided into three and four subspecies). The generic diagnosis is changed to encompass the specific characters of the new species.