Lymnaeidae

noun plural

Lym·​nae·​idae lim-ˈnē-ə-ˌdē 

: a family of thin-shelled air-breathing freshwater snails (superorder Hygrophila) that have an elongate ovoidal shell with a large opening and a simple lip and that include numerous species important as intermediate hosts of trematode worms see fossaria, galba, lymnaea

lymnaeid

-ˈnē-id 

adjective or noun