In the Eudoridoidea the gills can be withdrawn into a pocket for protection. Another name for the superfamily is the "Cryptobranchia" which basically means "hidden gills".

Characteristics :

This group of dorid nudibranchs lack radular teeth and feed by secreting digestive enzyme into sponges and sucking the partially digested tissue.

Photo : D. denisoni

Gills :

They have a prominent gill on the back

Rhinophores :

Usually with very swollen rhinophore stalks

Photo : D. denisoni