FISHES OF HAWAIIAN ISLANDS. 
381 
rounded; pectorals somewhat rounded; outer rays of ventrals filamentous, reaching first anal spine; 
ventral spine long, about 1.33 in head; depth of head about equaling its length; profile steep, 
slightly depressed or concave at junction of nape and occiput; snout not projecting, concurrent with 
profile; opercle unarmed; the nearly vertical margin of preopercle finely toothed, the spine at angle 
long, quite reaching lower base of pectoral, one or more short, sharp spines at its base below; subor- 
bital finely toothed; an anterior scaled lobe of interopercle with several conspicuous teeth or spinules. 
Color in alcohol, body sharply divided into 2 colors at a line running irregularly from sixth 
dorsal spine to ventral region; posteriorly black, with bluish reflections, including dorsal and anal 
fins, nearly to end of caudal peduncle; tips of middle rays of soft dorsal straw-yellow, extending a 
short distance on the upper part of the fin as a narrow margin; caudal abruptly straw-yellow; anterior 
part of body and spinous dorsal, including fifth spine, pectoral, and ventrals, pale yellow or straw; 
entire head with an irregular tint of purplish brown composed of fine punctulations on background of 
pale yellow; a broad black band, somewhat V-shaped, the apex up, from upper margin of eye over 
occiput and nape. The above description from an example 5.62 inches long obtained in Samoa by Dr. 
Jordan. 
Fig. 165 . — Holacanthus bicolor (Bloch); after Gunther. 
Numerous other smaller specimens vary slightly. The dorsal spines run xiv-xv, mostly xv. The 
ventral fins are not always so long; the preopercular spine in all cases is not quite so long, and there 
are finer teeth on interopercle and at the base of preopercular spine below. The color does not 
vary much. 
Hawaiian Islands and Polynesia. Not obtained by us, the only Hawaiian reference being that 
of Gunther. 
Chsetodon bicolor Bloch, Ichth., VI, 70, taf. 206, fig'. 1, 1788, no locality; doubtless East Indies. 
Holacanthus bicolor, Cuvier & Valenciennes, Hist. Nat. Poiss., VII, 168, 1831; Gunther, Fische der Sudsee, II, 51, taf. xxxix, 
fig. B, 1871 (Navigator and Sandwich islands). 
Family LXX1V. ZANCUDtE. — M oorish Idols. 
Body oblong, much compressed and elevated, covered with minute, rough scales; mouth small, 
with long, slender, brush-like teeth; no teeth on palate; bones of top of head thick and solid, develop- 
ing with age a conspicuous median horn on the forehead, wanting in the young; preopercle unarmed; 
dorsal single, with 7 spines, the third and succeeding spines prolonged into long filaments; inter- 
