Order Dictyoceratida Minchin, 1900

Abstract

Dictyoceratida Minchin (Demospongiae) is constituted of four families and thirty six described and valid genera, several additional gen- era are known but have not yet been described. Sponges are tough and flexible, they are hard if debris infiltrates the matrix, or the skele- tal mesh is condensed, soft when the density of the fibre skeleton in relation to soft tissue volume is reduced. The surface is typically conulose, except where densely armoured as in some species of Psammocinia. Fibres are anastomosing and, except in two genera, have a hierarchical arrangement with respect to diameter and surface orientation with primary, secondary and sometimes tertiary elements pres- ent. Fibre composition is homogeneous with growth laminae just apparent, or pithed and strongly laminated with bark and pith elements, the whole being always tightly adherent.