Shells, anatomy and genitalia of the putative hybrid populations of H. bicarinata and H. echinulata. Shells: 55 Pedregal de Dentro 56 Ribeira Formosa 57 Pico de Cabrita 58–59 Cabecos dos Bades 60 Pedregal de Fora. Genitalia and anatomy. Cabecos dos Bades: 61 whole genitalia excluding part of OSD, AG and gonads 62 section of penial papilla 63 penial papilla 64 inner walls of atrium and penis 65 mantle border. Pedregal de Dentro: 66 whole genitalia excluding part of OSD, AG and gonads 67 inner walls of atrium and penis 68 jaw 69 section of penial papilla 70 vaginal glands and vaginal appendage. Scale bars 1 mm.