196 BULLETIN 10 0, UNITED STATES NATIONAL MUSEUM 



frontal horn with age, not present in young. Preopercle unarmed, 

 Branohiostegals 4. Pyloric coeca 14. Intestines long. Vertebrae 

 22, of which 13 caudal. Scales minute and rough. Dorsal single, 

 spines 7, third and following prolonged as filaments; interspinal bone 

 projects before dorsal. Anal like soft dorsal, long, front ra3''s pro- 

 duced; small antrorse spine before anal. Caudal lunate. Pectoral 

 short. Ventral pointed. 



Genus ZANCLUS Cuvier 



Zanclus Cuvier, Hist. Nat. Poiss., vol. 7, 1831, p. 102. Type C'haeiodon 



cornutus Linnaeus, monotj^pic. 

 Gonopteras Gkay, Cat. Fish. Gronow, vol. 2, 1854, p. 77. Type Gonopterus 



morens Gr'ay, monotypic. 

 Gnathocentrum Guichenot, Ann. Soc. Maine et Loire, vol. 9, 1866, p. 4. 



Type Gnathocerdrum centrognathum Guichenot, monotypic. 



Body deeply ovoid. Head very deep. Snout and muzzle strongly 

 produced. Teeth in jaws biserial. Opercle without spine. Air 

 bladder large. Scales very small or indistinguishable. Head scaly 

 above and laterally. Lateral line continuous to caudal base. Soft 

 dorsal and anal anteriorly elevated. Paned fins subequal. 



Indo-Pacific. 



ZANCLUS CANESCENS (Linnaeus) 



Chaetodon canescens Linnaeus, Syst. Nat., ed. 10, vol. 1, 1758, p. 272. 

 East Indies; Syst. Nat., ed. 12, vol. 1, 1766, p. 460.— Gmelin, Syst. 

 Nat. Linn., vol. 1, pt. 3, 1789, p. 1240 ("America").— Walbaum, Arted. 

 Pise, vol. 3, 1792, p. 443 (on Linnaeus). — Forster, Fauna Indica, 1795, 

 p. 14.— Schneider, Syst. Ichth. Bloch, 1801, p. 219 (Indies). 



Chetodon canescens Bonnaterre, Tabl. Ichth., 1788, p. 80, pi. 43, fig. 166 

 (East Indies). 



Pomacanthus canescens Lacep^,de, Hist. Nat. Poiss., vol. 4, 1802, pp. 517, 

 519 ("South America"). 



Zanclus canescens Gxjnther, Cat. Fish, Brit. Mus., vol. 2, 1860, p. 493 

 (copied). — Bleeker, Atlas Ichth, Ind. N^erland., vol. 9, 1877, p. 78, pL 

 (4) 366, fig. 3 (Celebes, Amboina). — Jordan and Fowler, Proc. U. S. 

 Nat. Mus., vol. 25, 1902, p. 549 (Misaki). — Franz, Abh. Bayer. Akad. 

 Wiss., vol. 4. suppl., vol. 1, 1910, p. 50 (Aburatsubu). — Weber, Siboga 

 Exp., vol. 57, Fische, 1913, p. 325 (Karkaralong Island and Rotti). — 

 McCuLLOcH, Mem. Queensland Mus., vol. 7, pt. 4, 1922, p. 242 (Capri- 

 corn Group). — Fowler, Bishop Mus. Bull., No. 22, 1925, p. 12 (Guam), 

 p. 28 (Honolulu), p. 34 (Samoa). — Fowler and Ball, Bishop Mus. Bull., 

 No. 26, 1925 (1926), p. 18 (Johnston Island, French Frigate Shoals, 

 Laysan). — Fowler, Proc. Acad. Nat. Sci. Phila., 1927, p. 287 (Philip- 

 pines). — Herre, Philippine Journ. Sci., vol. 34, No. 4, Dec. 1927, p. 472, 

 pi. 8 (Legaspi and Manila). — Barnard, Ann. South Afric. Mus., vol. 21, 

 pt. 2, Oct. 1927, p. 782, pL 31, fig. 3 (Mossel Bay, Natal, Delagoa Bay). 



Chaetodon cornutus Linnaeus, Syst. Nat., ed. 10, vol 1, 1758, p. 273. East 

 Indies; Syst. Nat., ed. 12, vol. 1, 1766, p. 461.— Bloch, Naturg. Ausl. 

 Fische, vol. 3, 1787, p, 72, pi. 200, fig. 2 (East Indies).— Gmelin, Syst. Nat. 

 Linn., vol. l,pt. 3, 1789, p. 1241 (India). — Walbaum, Arted. Pise, vol. 3, 

 1792, p. 442 (on Linnaeus and Bloch). — Forster, Fauna Indica, 1795, p. 



