†Chitinozoa Eisenack, 1931 - chitinozoans Order †Operculatifera Eisenack, 1931 Family †Desmochitinidae Eisenack, 1931 Subfamily †Pterochitininae Paris, 1981 Genus Bion H. Lohmann (1904) 0 †Bion perivelatum Eisenack (1937) see Pterochitina perivelata (Eisenack, 1937)