When originally proposed in 1872, the new fossil-genus includes two monotypic, previously validly published fossil-genera, Clypeina Michelin (Iconogr. Zoophyt.: 177. 1844) and Prattia d'Archiac (in Mém. Soc. Géol. France, Series 2, 3(Mémoire 6): 407. 1850).