Suberites carnosus var. incrustans Topsent, 1900

Van Soest, Rob W. M., 2024, Correcting sponge names: nomenclatural update of lower taxa level Porifera, Zootaxa 5398 (1), pp. 1-122 : 86

Suberites carnosus var. incrustans Topsent, 1900

Suberites carnosus incrustans Topsent, 1900: 235–236 (no illustration).

Suberites carnosus var. incrustans ; Topsent 1925a: 633; Bibiloni 1981: 16.

Suberites carnosus f. incrustans ; Cabioch 1968: 216; Vacelet 1976: 174.

The form was described by Topsent predominantly from the Pas-de-Calais region (W coast of France) and from Banyuls (Mediterranean coast of France). The original text of Topsent (1900) would indicate that he considered the S. c. incrustans (as well as the other mentioned S. carnosus forms) as infrasubspecific, i.e. growth forms or morphotypes of a species, rather than proper (sub)specific taxa. But his assignment to a variety in 1925a and followed by a forma designation by Cabioch and Vacelet indicated it was subsequently considered a distinct taxon. No clear type material was indicated by Topsent. The description reminds strongly of Protosuberites denhartogi Van Soest & De Kluijver (2003: 403 , fig. 1 = Prosuberites epiphytum sensu Topsent 1900: 236 , not Lamarck 1814) described from the Oosterschelde, the Netherlands, 54.64°N 3.91°E, depth 0–1 m (holotype ZMA Por. 04403). Topsent (1900: 236) also pointed this out (as P. epiphytum ), but refuted conspecificity by alleging that the tylostyles of the two species were different, without explaining the difference. A further species with similarity to the present form is Protosuberites stephensae Van Soest & Hooper, 2020: 35 , a recent new name for the preoccupied P. incrustans (sensu Stephens 1915b as Laxosuberites ). The combination Suberites carnosus incrustans is a junior primary homonym of Suberites incrustans Hansen, 1885 (currently Protosuberites incrustans ), and it needs to be renamed. I propose to assign the present forma to the synonymy of Protosuberites denhartogi Van Soest & De Kluijver, 2003 , thus removing the homonymy.