You can search the complete taxonomic tree of the species in the database. Click "Phylum" to get back to to the starting point. The thumbnails show examples of the Class, Order etc.

Phylum	Class	Order	Family	Species
Mollusca	Gastropoda	Nudibranchia	Chromodorididae
Mollusca	Gastropoda	Nudibranchia	Discodorididae
Mollusca	Gastropoda	Nudibranchia	Facelinidae
Mollusca	Gastropoda	Nudibranchia	Flabellinidae
Mollusca	Gastropoda	Nudibranchia	Glaucidae
Mollusca	Gastropoda	Nudibranchia	Phyllidiidae
Mollusca	Gastropoda	Nudibranchia	Polyceridae