Microcionina with terminally spined ectosomal styles, rarely modified to quasidiactinal or diactinal forms; three skeletal regions defined by the presence of different forms of structural styles:(1) choanosomal (axial) skeleton (with spongin fibres enveloping principal styles echinated by acanthose or smooth styles; in two groups this is replaced by a basal or axial renieroid skeleton of smooth or acanthose styles or strongyles, with or without echinating spicules); (2) subectosomal (extra-axial or extra-fibre)skeleton (with individual or tracts of auxiliary styles ascending to the surface); and (3) ectosomal skeleton (with smaller auxiliary styles forming a surface crust tangential, paratangential or perpendicular to the surface). One or more skeletal regions may be lost or modified. Megascleres predominantly smooth styles but may be modified and/or supplemented by quasidiactinal or diactinal forms, or lost completely and replaced with detritus. Microscleres include palmate isochelae and diverse forms of toxas.
Hooper, J.N.A. 2002. Family Microcionidae Carter, 1875. Pp. 432-468. In Hooper, J. N. A. & Van Soest, R. W. M. (ed.) Systema Porifera. Guide to the classification of sponges. 1 (Kluwer Academic/ Plenum Publishers: New York, Boston, Dordrecht, London, Moscow).