Class Nuda
These are sponges that lack intercellular jelly. In other words, the star-shaped cells and the amoeba cytes form a network through which water percolates, and there are no inhalant or exhalant canals.
Glass sponges (Order Hexactinellida) Sponges of this order are characterized by siliceous spicules based on a hexaradiate or six-rayed plan.
Suborder Hexasterophora
Glass sponges in which the typical spicule is a hexaster, and has therefore a six-rayed star shape. Typical examples of this suborder are Venus’s Flower Basket (Euplectella, Aphrocallistes, Farrea).
Suborder Amphidiscophora
Another suborder of the Hexactinellida or glass sponges in which the typical spicule is an amphidisc. In the Single-rod Sponge (Monoraphis) becomes a rod almost a yard long, with the sponge situated at the upper end. Other typical genera of the suborder are Hyalonema and Pheronema.