Fam. 7.--Phyllidiidae. Pharynx suctorial; branchiae surrounding the body, between the mantle and foot. Phyllidia. Fryeria.
The last three families constitute the sub-tribe Porostomata, characterized by the reduction of the buccal mass, which is modified into a suctorial apparatus.
Tribe 3.—Eolidomorpha (Cladohepatica). The whole of the liver contained in the integuments and tegumentary papillae. Genital duct diaulic; male and female apertures contiguous. The anus is antero-lateral, except in the Proctonotidae, in which it is median. Tegumentary papillae not ramified, and containing cnidosacs with nematocysts.
Fam. 1.—Eolididae. Dorsal papillae spindle-shaped or club-shaped. Eolis, British. Facelina, British. Tergipes, British. Gonieolis. Cuthona. Embletonia. Galvina. Calma. Hero.
Fam. 2.—Glaucidae. Body furnished with three pairs of lateral lobes, bearing the tegumentary papillae; foot very narrow; pelagic. Glaucus.
Fam. 3.—Hedylidae. Body elongated; visceral mass marked off from foot posteriorly; dorsal appendages absent, or reduced to a single pair; spicules in the integument. Hedyle.
Fam. 4.—Pseudovermidae. Head without tentacles; body elongated; anus on right side. Pseudovermis.
Fam. 5.—Proctonotidae. Anus posterior, median; anterior tentacles, atrophied; foot broad. Janus, British. Proctonotus, British.
Fam. 6.—Dotonidae. Bases of the rhinophores surrounded by a sheath; dorsal papillae tuberculated and club-shaped, in a single row on either side of the dorsum; no cnidosacs. Doto, British. Gellina. Heromorpha.
Fam. 7.—Fionidae. Dorsal papillae with a membranous expansion; male and female apertures at some distance from each other; pelagic. Fiona.