Venus mercenaria vs Mercenaria mercenaria

Venus mercenaria and Mercenaria mercenaria both are nouns.

Word	Noun	Adjective	Verb	Adverb
Venus mercenaria	Yes	No	No	No
Mercenaria mercenaria	Yes	No	No	No

As nouns, Venus mercenaria and Mercenaria mercenaria are synonyms defined as:

Venus mercenaria and Mercenaria mercenaria: an edible American clam; the heavy shells were used as money by some American Indians

Other synonyms of Venus mercenaria include hard-shell clam, hard clam, quahaug, quahog, round clam.

Venus mercenaria (noun)	Mercenaria mercenaria (noun)
an edible American clam; the heavy shells were used as money by some American Indians	an edible American clam; the heavy shells were used as money by some American Indians