MATERIAL AND METHODS
Thick sections of freshly collected material were made with a surgical blade, soaked in Xylene-Phenol (1:1) solution before mounting on glass slides in DPXฎ and examined under the light microscope at 100–400 X magnifi cation. Dissociated spicule suspensions were obtained by boiling in concentrated nitric acid (siliceous spicules) and subsequently mounted on brass stubs for examination under a JEOL scanning electron microscope (SEM). Residues of the spicule suspensions were also mounted on glass slides in DPX measurements of spicule dimensions under the light microscope. Spicule size data are given as minimum–average–maximum based on a minimum of 25 measurements for each spicule type. Images of specimens, sections and SEM preparations were obtained digitally. Systematic and the order of treatment of the families and genera follow the Systema Porifera (Hooper & van Soest, 2002) and the World Porifera Database (van Soest et al., 2012).