Vesicomyidae (Mollusca: Bivalvia) of the genera Vesicomya, Waisiuconcha, Isorropodon and Callogonia in the eastern Atlantic and the Mediterranean

Five new species of Vesicomyidae are described and five other previously known from the eastern Atlantic and Mediterranean are revised: Vesicomya atlantica (E.A. Smith, 1885), N-Atlantic between the Azores and Cape Verde Basin, 1800-3225 m; Vesicomya adamsi (E.A. Smith, 1885), from Sierra Leone to Namibia, 4400-5124 m; Waisiuconcha haeckeli sp. nov., off Mauritania, 600-1200 m; Isorropodon perplexum Sturany, 1896, eastern Mediterranean, 1950-2500 m; Isorropodon bigoti sp. nov., off Congo (Brazzaville), 150 in and off Mauritania, 900-1200 m; L curtum sp. nov. from off Mauritania, 900-1200 m; L striation (Thiele & Jacckel, 1931) from the Bight of Biafra, 2492 in; Callogonia cyrili sp. nov., off Morocco, 1805 m; Callogonia mauritanica sp. nov., off Mauritania 9001200 m; Vesicomya chuni Thiele & Jacckel, 193 1, from the Bight of Biafra, 2492 in. Detailed data on anatomy of the genus Isorropodon (formerly placed in the Trapezidae) are presented for the first time and it is shown to be a valid taxon belonging to the Vesicomyidae. Three other species described by Thiele & Jacckel (193 1) are briefly discussed A parsimony analysis for all eastern Atlantic Vesicomyidae using size, hinge teeth and other shell characters supported two well-defined main groupings: Vesicomya and Waisiuconcha on the one hand, lsorropodon and Callogonia on the other, whereas the position of the remaining species could not be resolved. The possible relationships of Vesicomya and Kelliella (Kelliellidae) are briefly discussed, and it is concluded that they should be kept as separate.