neritid vs seasnail

neritid and seasnail both are nouns.

Word	Noun	Adjective	Verb	Adverb
neritid	Yes	No	No	No
seasnail	Yes	No	No	No

As nouns, seasnail is a hypernym of neritid; that is, seasnail is a word with a broader meaning than neritid:

neritid: operculate seasnail of coastal waters with a short spiral shell
seasnail: any of several creeping marine gastropods with a spirally coiled shell: whelks, tritons, moon shells, neritids

neritid (noun)	seasnail (noun)
operculate seasnail of coastal waters with a short spiral shell	small tadpole-shaped cold-water fishes with pelvic fins forming a sucker; related to lumpfish
	any of several creeping marine gastropods with a spirally coiled shell: whelks, tritons, moon shells, neritids