What are the classes of phylum porifera and examples?

There are four classes in the phylum porifera. The following are the classes with example.

1. Calcarea. E.g - Clathrina clathrus
2. Hexactinellida. E.g - Venus flower basket.
3. Demospongiae E.g - Red encrusting sponge.
4. Homoscleromorpha E.g - Oscarella lobularis