Leucettida is an order

Order (biology)

In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...

 in the subclass of Calcinea

Calcinea

Calcinea is a subclass of the calcareous sponges....

.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