Onchidiidae: a family of air-breathing sea slugs.

Philinidae is a family of medium-sized sea slugs, marine opisthobranch gastropod mollusks.

Lomanotidae is a family of sea slugs, marine gastropod mollusks in the superfamily Tritonioidea.

Arminidae is a family of sea slugs, marine gastropod mollusks in the superfamily Arminoidea.

Hermaeidae is a taxonomic family of sacoglossan sea slugs.

Doridomorphidae is a taxonomic family of colorful sea slugs or nudibranchs.

Calmidae is a taxonomic family of sea slugs.

Glaucidae is a taxonomic family of colorful sea slugs.

Limapontiidae is a taxonomic family of small to minute sacoglossan sea slugs.

Aglajidae is a family of often colorful, medium-sized, sea slugs, marine opisthobranch gastropod mollusks.