New species of Thyasiridae from a methane seepage area off Concepción, Chile Author Oliver, P. Graham Department of Biodiversity and Systematic Biology, National Museum of Wales, Cathays Park, Cardiff, CF 10 3 NP, Wales, UK. E-mail: graham. oliver @ nmgw. ac. uk Universidad Católica del Norte, Facultad de Ciencas del Mar, Larrondo 1281, Coquimbo, Chile. E-mail: jsellane @ udec. cl Author Sellanes, Javier text Zootaxa 2005 2005-12-08 1092 1 1 20 https://biotaxa.org/Zootaxa/article/view/zootaxa.1092.1.1 journal article 10.11646/zootaxa.1092.1.1 1175­5334 5051152 11F595CF-C728-4530-8362-32D585A0C8AC Genus Thyasira Leach ms in Lamarck, 1818 Type species Tellina flexuosa Montagu, 1803 Definition Fragile shells, ovate to ovate­polygonal in outline with a posterior sulcus; escutcheon variably expressed, absent to deep, with or without an auricle producing a submarginal sulcus. Hinge teeth lacking or as a single “cardinal” tubercle, ligament sunken. Anterior adductor scar elongate, posterior adductor scar ovate, pallial line entire. Ctenidium with two demibranchs, lateral body pouches large and multilobed, foot vermiform, heel obsolete, toe developed.