Leucettida

(invertebrate zoology) An order of calcareous sponges in the subclass Calcinea having a leuconoid structure and a distinct dermal membrane or cortex.

An order of the subclass Calcinea in the class Calcarea. These sponges have either a radiate arrangement of the flagellated chambers or a leuconoid structure. A distinct dermal membrane or cortex is present. The spongocoel is not lined with choanocytes; these cells are restricted to the flagellated chambers. Two families are recognized, the Leucascidae and Leucaltidae. See also Calcarea.