Guide to the orders, families and genera of subclass Calcaronea
taken from 'Sponguide' by J.N.A. Hooper (Queensland Museum, Brisbane)
Definition: Calcarea with incubated amphiblastula larvae flagellated only on the anterior half; nuclei of choanocytes
apical, and the flagellum arises directly from the nucleus; spicules are triradiate and sagittal (two
rays are paired and the third ray is longer than the others), as well as free monaxonic (monactinal or
diactinal) forms; aquiferous system ranges from asconoid to leuconoid grades of construction.
Order 
