planorbis
Pla*nor"bis, n. Etym: [NL., fr. L. planus flat + orbis a circle.] (Zoöl.) Defn: Any fresh-water air-breathing mollusk belonging to Planorbis and other allied genera, having shells of a discoidal form.
Pla*nor"bis, n. Etym: [NL., fr. L. planus flat + orbis a circle.] (Zoöl.) Defn: Any fresh-water air-breathing mollusk belonging to Planorbis and other allied genera, having shells of a discoidal form.