Conus olivaceus; Print; Fossil Conus pelagicus from the Pliocene of Cyprus. Conus is a genus of predatory sea snails; or cone snails; marine gastropod mollusks in the family Conidae. Prior to 2009; cone snail species had all traditionally been grouped into the single genus Conus. However; Conus is now more precisely defined; and there are several other accepted genera of cone snails. For a list of the currently accepted genera; see Conidae.