Opisthobranchia

Từ điển WordNet v3.1 - WordNet Dictionary

noun

gastropods having the gills when present posterior to the heart and having no operculum: includes sea slugs;
sea butterflies;
sea hares
• Syn:
subclass Opisthobranchia
• Hypernyms:
class
• Member Holonyms:
Gastropoda, class Gastropoda, Gasteropoda, class Gasteropoda
• Member Meronyms:
Nudibranchia, order Nudibranchia