Alveospongia, Santos, George Garcia, Pinheiro, Ulisses, Hajdu, Eduardo & Soest, Rob Van, 2016

Santos, George Garcia, Pinheiro, Ulisses, Hajdu, Eduardo & Soest, Rob Van, 2016, New Genus and species of Heteroxyidae from Brazil (Axinellida: Demospongiae: Porifera), with a revised identification key for the family, Zootaxa 4158 (1), pp. 105-116 : 107

Genus Alveospongia gen. nov.

Diagnosis. Heteroxyidae with saccular or alveolar shape, with rugose-microhispid surface. Ectosomal skeleton a thick crust of tangentially placed styles/strongyles. Choanosomal skeleton a confused arrangement of single styles/ strongyles, or widely spaced reticulate bundles of these megascleres with little spongin. Megascleres are a single category of styles/strongyles. Microscleres sinuous acanthomicrostrongyles stewn at random. Type species. Alveospongia sinuosclera sp. nov. (designation herein).

Etymology. The generic name, Alveospongia is used as a noun, derived from the Latin alveos (cavity, trough, pit, hollow, channel), in reference to the saccular morphology of the holotype of the species described below.

Remarks. Table 1 summarizes the main morphological characters of all genera currently assigned to Heteroxyidae according to van Soest et al. (2016), and contrasts these to the characters observed in Alveospongia gen. nov. No other genus in the family has a saccular-alveolar growth form and sinuous acanthomicrostrongyles, but the (para)tangential ectosomal architecture is shared with Julavis and Parahigginsia ; the vague choanosomal reticulation is also present in Desmoxya , Julavis , Microxistyla and Negombo ; and styles occur in every genus, except Didiscus , Heteroxya and Parahigginsia . This combination of characters makes us confident that assignment of Alveospongia gen. nov. to Heteroxyidae is the best allocation in the current classification, at the same time recognizing that a new genus is also warranted. A revised identification key for genera of Heteroxyidae is provided below, including the new genus proposed here, as well as Alloscleria and Desmoxya , absent from the key proposed by Hooper (2002), when both were considered junior synonyms of Halicnemia Bowerbank, 1864 and Higginsia Higgin, 1877 , respectively.