Usually ovate in shape, some tending to elongate with a broad mantle skirt. The mantle is thick and reinforced with a network of spicules. It is frequently covered with pustules or tubercles.
The oral tentacles are more auriculate than tentacular. The rhinophores are lamellate, sometimes with raised sheaths, and they can retract into pockets whose margins are either smooth or (rarely) carry pustules or papillae. The usually tripinnate gills can retract beneath the mantle into a pocket that also contains the anal papilla.
In some species the gills can be compressed and spread posteriorly like a fan and topped by a notal flap. Doridids are often well camouflaged upon their sponge prey.