sponge. He argued that the distinct cup-shaped top
of C. patera does not warrant a separate genus. However,
Vosmaer (1911) did not agree with Topsent (1909) and
preferred to retain Poterion as a genus. He also said “there
are suffi cient anatomical grounds to keep Poterion and Cliona
apart” but did not provide supporting evidence. However,
Rützler (2002) supported Topsent’s decision, and Cliona
patera fi tted well in the defi nition of the family Clionaidae
and the genus Cliona in Rützler’s revision. This decision is
supported by the fresh excavation marks and characteristic clionaid ostial and oscular papillae observed in situ in this study. We also feel that the sole character of form, though unique in a spectacular fashion in the case of C. patera, is not suffi ciently strong justifi cation to erect a separate genus. Genetic data will shed more light on the placement of C.
patera in relation to other genera in the Clionaidae and other Cliona species, especially C. celata. Until then, C. patera
seems well placed in the genus