The (Euopisthobranchia) -
(Umbraculoidea) - superfamily

(Umbraculidae)
- family

(Tylodinidae)
- family
(Anaspidea)

(Akeridae)
- family

(Aplysiidae)
- family
(Runcinacea)

(Runcinidae)
- family

(Ilbiidae)
- family
(Pteropoda)
The Sea Butterflies
(Thecosomata)
-
The Sea Angels
(Gymnosomata)
-
(Cephalaspidea)

(Acteonoidea)
- superfamily

(Bulloidea)
- superfamily

(Cylindrobulloidea)
- superfamily

(Diaphanoidea)
- superfamily

(Haminoeoidea)
- superfamily

(Philinoidea)
- superfamily

(Ringiculoidea)
- superfamily