Wecomedon Jarrett & Bousfield, 1982, a replacement name for the amphipod genus Psammonyx Bousfield, 1973 (Crustacea, Amphipoda, Tryphosidae), preoccupied by Psammonyx Döderlein, 1892 (Foraminifera, Astrorhizida, Ammovolummidae)