Subgenus (Tristichotrochus) Ikebe, 1942
(5-4-1-3-2-11-2-4-22-0-0-0-0) Ref. Lindner, 1977 p 37 Vaught, 1989 p 9 formosensis (E. A. Smith, 1907) (5-4-1-3-2-11-2-4-22-1-0-0-0) Formosa Top Ref. Abbott & Dance, 1982 p 39 c Lindner, 1977 pl 5 c
(5-4-1-3-2-11-2-4-22-0-0-0-0) Ref. Lindner, 1977 p 37 Vaught, 1989 p 9
formosensis (E. A. Smith, 1907) (5-4-1-3-2-11-2-4-22-1-0-0-0) Formosa Top Ref. Abbott & Dance, 1982 p 39 c Lindner, 1977 pl 5 c