Genus Pachynaias P. Fischer & H. Crosse, 1894
(3-5-4-0-4-9-2-T3-42-0-0-0-0-0) Syn. Arotonaias E. C. v Martens, 1900; Ptychoderma C. T. Simpson, 1900 Ref. Vaught, 1989 p 123