FISHES OF THE PHnjIPPINE AND ADJACENT SEAS 79 



CHAETODON SEMEION Bleeker 



Chaetodon semeion Bleeker, Nat. Tijds. Nederland. Indie, vol. 8, 1855, p. 

 450. Cocos Keeling Islands, Indian Ocean. — Gunther, Cat. Fish. Brit. 

 Mus., vol. 2, 1860, p. 7 (copied); Journ. Mus. Godeffro}-, vol. 2-3, Heft 

 5-6, 1874, p. 37, pi. 28 (Society Islands and Samoa). — Fowler, Proc. 

 Acad. Nat. Sci. Philadelphia, 1899, p. 492 (Thornton Island). — Jordan 

 and Seale, Bull. Bur. Fish., vol. 25, 1905 (1906), p. 343 (Apia).— Ahl, 

 Arch. Naturg., vol. 89, abth. A, Heft 5, 1923, p. 69 (Samoa, New Pome- 

 rania, New Guinea). — Fowler and Ball, Bishop Mus. Bull., No. 26> 

 1925 (1926), p. 17 (Wake Island). 



Tetragonoptrus (Rabdophorus) sevieion Bleeker, Atlas Ichth. Ind. Neer- 

 land., vol. 9, 1877, p. 37, pi. (12) 374, fig. 5 (Cocos, Celebes, Coram). 



Depth 1% to 13^; head 3 to 3^, width 2 to 2>^. Snout 2% to 3 

 in head; eye zy^ to 43^, 1% to 1% in snout, 114, to 13^ in interor- 

 bital; maxillary 3^ to % in snout, 33^^ to 4 in head; interorbital 2>% 

 to ?>}/2, convex. Gill rakers 3 + 14, short points, 3^ of gill filaments, 

 which equal eye. 



Scales 30 or 31 between gill opening and caudal base; tubes 28 to 

 32 in lateral line; 8 or 9 scales above lateral line, 13 or 14 below. 

 Scales with 11 or 12 basal radiating striae; apical denticles 145 to 

 160, with 23 to 35 series of basal segments transversely; circuli fine. 



D. XIII or XIV, 24, i or 25, i, last spine 2}4, to 23^ in head, second 

 elongated ray 1% to 2}/^ in combined head and body; A. Ill, 21, i 

 or 22, I, third spine 2 to 2% in head, tenth ray iVa to 2; least depth 

 of caudal peduncle 3 to 3%; caudal 1 to 13^, deeply emarginate with 

 upper and lower ends slender points; pectoral 13^3 to 1%; ventral 



Brown, little paler on abdomen. Broad black band from pre- 

 dorsal to eye and down across cheek where wider, though not 

 extended on chest or breast. Each scale on body beginning behind 

 vertical of pectoral base with small dusky apical dot, also not on 

 caudal peduncle or anal base; as rows of scales below lateral line 

 slightly inclined, likewise series of dots. Soft dorsal and anal edges 

 narrowly white, each with dusky submarginal line. Black median 

 band diffuse and narrow at first begins on spinous dorsal posteriorly, 

 then extends gradually expanding to last dorsal rays. Black blotch 

 on last anal rays subbasally and narrowed forward. Caudal and 

 paired fins uniformly pale brown. 



Keeling Islands, East Indies, Polynesia. 



514 [1555]. Biri Channel, Balicuatro Island. June 2, 1909. Length 140 mm. 

 General color cadmium yellow. Forehead and snout posteriorly dusky. 

 Ocular bar equal to eye above, somewhat broader below, extends across intero- 

 percle but not on chest. Black central band from last dorsal spine to verti- 

 cal edge of fin, somewhat yam-shaped, rounded on vertical portion. On sides 

 behind shoulder each scale with small black dot in central margin, these 

 extending on soft dorsal base to black band; space above anal base and caudal 

 peduncle immaculate, also breast and belly from level of pectoral to front 

 of anal without spots. Dorsal spines and membranes at tips, including all 



