Valletia Munier-Chalmas 1873

GenusValletiaMunier-Chalmas, 1873 Type species. Valletia tombecki Munier-Chalmas, 1873 [= Valletia germani (Pictet & Campiche, 1868)], by monotypy. Remarks. Valletia differs from Diceras in the possession of a shortened external ligament; the attachment of the myophores to the hinge plate; and a derived inverse dentition sensu Douvillé (1887, 1896): a large anterior (2 a) and a small posterior tooth (2 b) in the left valve are separated by a deep central socket, which accommodates a corresponding, usually arched, large central tooth (1) in the right valve (Skelton 2013 a; Schneider and Skupien 2015; Rineau et al. 2020).