Radiella Schmidt, 1870

Diagnosis. Circular lenticular or hemispherical Polymastiidae . The skeleton of the basal surface of the sponge is composed of an envelope of principal subtylostyles or styles covered by a thin palisade of ectosomal tylostyles. The upper surface is composed of one or two layers of tylostyles. The choanosomal skeleton is composed of diverging tracts emanating from a central nucleus at the base of the sponge and by groups of fusiform tylostyles. The inhalant and exhalant apertures are grouped on papillae (Boury-Esnault 2002).