singularius, Heniochus Smith [H. M.] & Radcliffe [L.] 1911:321, Fig. 2 [Proceedings of the United States National Museum v. 40 (no. 1822); ref. 10246] Alibijaban, Ragay Gulf, Luzon Island, Philippines. Holotype: USNM 67354. Additional material: many localities. First author is H. M. Smith. •Valid as Heniochus singularius Smith & Radcliffe 1911 -- (Burgess 1978:255 [ref. 700], Allen 1980:163 [ref. 22764], Ida in Masuda et al. 1984:186 [ref. 6441], Allen & Swainston 1988:98 [ref. 25477], Blum 1989:12 [ref. 37553] as singularis, Randall et al. 1990:234 [ref. 15987], Allen 1997:150 [ref. 23977], Chen et al. 1997:117 [ref. 26476], Kuiter 1997:224 [ref. 25488], Randall et al. 1997:234 [ref. 25919], Myers 1999:168 [ref. 23965], Allen 2000:89 [ref. 37268], Pyle in Randall & Lim 2000:624 [ref. 25122], Nakabo 2000:885 [ref. 25182], Laboute & Grandperrin 2000:303 [ref. 25191], Allen 2000:106 [ref. 25868], Hutchins 2001:265 [ref. 25841], Hutchins 2001:36 [ref. 25847], Pyle 2001:3264 [ref. 26117] as singularis, Nakabo 2002:885 [ref. 26193], Allen & Adrim 2003:43 [ref. 26830], Smith et al. 2003:302 [ref. 27125], Myers & Donaldson 2003:630 [ref. 27495], Randall et al. 2004:19 [ref. 27624], Adrim et al. 2004:122 [ref. 27715], Randall 2005:328 [ref. 28239] as singularus, Randall et al. 2005:125 [ref. 28745], Allen et al. 2006:1300 [ref. 29090], Satapoomin 2009:191 [ref. 30463], Motomura et al. 2010:139 [ref. 31256], Zuo & Tang 2011:1003 [ref. 32151], Allen & Erdmann 2012:540 [ref. 31980], Koeda et al. 2016:58 [ref. 35333], Fricke et al. 2019:192 [ref. 36673], Habib & Islam 2020:Supplementary table p. 22 [ref. 38321], Heemstra & Heemstra 2022:467 [ref. 39746]). Current status: Valid as Heniochus singularius Smith & Radcliffe 1911. Chaetodontidae: Heniochinae. Distribution: Indo-West Pacific: Chagos Archipelago, Maldives, Sri Lanka and Bangladesh east to Micronesia and Samoa, north to Japan, south to northern Australia. Habitat: marine.