The other is Arcinella cornuta Conrad, 1866 The Spiny Jewel Box Leslie Dear Listers, http://www.idscaro.net/ext/f_myst/whois.htm my mysteries pages, has two new entries which are waiting for your help. One, something like a Chama, comes from southern USA, but can't tell you if it's from the Western or Eastern side. The second, maybe a Glycymeris, comes from European Atlantic shores. Thank you for your help in ID, and merry Xmas to all! O.Caro