Cacospongia dendroides var. dura Poléjaeff, 1884

(Fig. 1B)

Cacospongia dendroides var. dura Poléjaeff, 1884: 60, pl. VI fig. 14, pl. VIII fig. 1.

Poléjaeff (1884: 60) erected two varieties for his Cacospongia dendroides (not: Hircinia dendroides Schmidt, 1862). This variety described from Challenger Exped. Stat. 208, Visayan Sea, Eastern Philippines, 11.6167°N 123.5167°E, depth 33 m (holotype BMNH 1885.8.8.30, fide Hooper & Wiedenmayer, 1994: 235), is here named as the nominotypical variety because it was mentioned first. Nominotypical infraspecific taxa must be named the same as the species (ICZN art. 47.1), so the var. dura it is to be re-named C. dendroides var. dendroides Poléjaeff, 1884 . Von Lendenfeld (1889) transferred the species with both varieties to the genus Hircinia (= Ircinia), which caused the name to become a junior secondary homonym of Hircinia dendroides sensu Schmidt, 1862 . Van Soest & Hooper (2020: 22) proposed Ircinia polejaeffi as replacement name for Cacospongia dendroides sensu Poléjaeff, 1884, but these authors omitted to discuss the varieties. The variety dura as the typical variety is a junior synonym of Ircinia polejaeffi Van Soest & Hooper, 2020 . The var. friabilis was elevated to species rank as Hircinia (= Ircinia) friabilis by Von Lendenfeld (1889: 566) (cf. below).

Burton (1934a: 582) discussed the species and its two varieties on the basis of material from the Great Barrier Reef (not the original specimens) and as usual refuted the importance of the differences. He considered them to belong to the same species along with Ircinia schulzei Dendy, 1905 .