dichrous, Chaetodon Günther [A.] 1869:239, Pl. 16 [Proceedings of the Zoological Society of London 1869 (pt 2) (art. 4) (for 8 Apr. 1869); ref. 13284] St. Helena Island, South Atlantic. Holotype (unique): BMNH 1868.6.15.18. •Valid as Chaetodon dichrous Günther 1869 -- (Burgess 1978:343 [ref. 700], Allen 1980:161 [ref. 22764]). •Valid as Prognathodes dichrous (Günther 1869) -- (Edwards & Glass 1987:640 [ref. 9166], Blum 1989:12 [ref. 37553], Maugé 1990:839 [ref. 17126] as dicrous, Burgess 2001:62 [ref. 25030], Smith et al. 2003:302 [ref. 27125], Trunov 2006:476 [ref. 28786], Wirtz et al. 2014:8 [ref. 33516], Bailly in Carpenter & De Angelis 2016:2672 [ref. 34618], Brown et al. 2019:178 [ref. 36444]). Current status: Valid as Prognathodes dichrous (Günther 1869). Chaetodontidae: Chaetodontinae. Distribution: Southern-central Atlantic: Ascension and Saint Helena islands, Grattan Seamount. Habitat: marine.