Family Chalinidae Gray 1867

Diagnosis. Thickly encrusting, cushion-shaped, ramose or tubular growth forms; cushion-shaped sponges commonly with oscular chimneys or mounds. Consistency soft to rather firm, also spongy. Colour purple, violet, pink, brown, blue or green, occasionally white. Megascleres smooth oxeas or strongyles, microscleres, if present, are sigmas, toxas, raphides or microxeas. Choanosomal skeleton a delicate reticulate choanosomal skeleton of uni-, pausi- or multispicular primary lines, which are regularly connected by unispicular secondary lines. Ectosomal skeleton, if present, a regularly hexagonal, unispicular, tangential reticulation (modified from de Weerdt 2000, 2002).

Remarks. De Weerdt (2000) included a definition of family Haplosclerida which was primarily a description of the choanosomal and ectosomal skeletons, important characters lacking from the 2002 diagnosis (de Weerdt 2002). We have expanded the original diagnosis to include these details.