FISHES OF THE PHOEN^IX AND SAMOAN ISLANDS 139 



4a. Fourth and fifth dorsal spines longest but in adults shorter than head, 

 all spines rigid and pungent ; ground color of body blackish with a 

 pale transverse band from origin of dorsal across operculum to breast 

 and a second pale band fi'om fifth to eighth dorsal spines to top of 

 caudal peduncle and on its upper posterior portion ; anal black, very 

 narrow white line along posterior margin of fin ; soft dorsal with a 

 pale band on posterior margin ; a triangular black band from last 

 three dorsal spines to base of last soft rays, continuing on upper 

 posterior part of caudal peduncle ; spiny dorsal black except where 

 pale band from body extends on lifth to eighth spines ; pectoral dusky, 

 caudal dusky; dorsal rays XI, 22 or 23; anal III, 17 or 18, pectoral 



about 15; scale rowj? about 50 to 55 Heniochus varius (Cuvier) 



46. Fourth dorsal spine prolonged, longer tlian head in adults and in 

 certain species llexible and produced into a filament. 

 5a. Two wide black transverse bands across body, one from front of spiny 

 dorsal to pelvics and including them ; the second behind long pro- 

 duced filamentous fourth spine from fifth to tenth spines down- 

 ward and backward to last half of anal fin and across lower anterior 

 corner of caudal peduncle; a black band passes from supraorbital 

 region to eye but not continued below it ; upper part of snout black- 

 ish, rest of head pale; pectoral fin base black but fin pale; caudal 

 fin pale ; soft dorsal pale ; ventral or anterior margin of anal fin 

 blackish ; dorsal rays XI or XII, 24 to 27 ; anal III, 16 to 19 ; scales 



about 44 to 46 Heniochus acuminatus (Linnaeus) 



5b. Three black transverse bands across head and trunk. 



6a. A wide black band beginning just before origin or dorsal and 

 passing across pectoral fin base to pelvics, front edge passing 

 from front of eye to insertion of pelvics; second band extending 

 from prolonged and flexible fourth spine of dorsal downward 

 and backward to soft rays of anal fin ; third extending from 

 across basal region of soft dorsal to top of caudal peduncle; 

 midline of snout blackish ; tip of upper lip blackish ; pectoral 

 pale ; caudal fin pale except where black on peduncle extends on 

 base of soft rays; posterior margin of anal white dorsally; tip 

 of prolonged fourth dorsal spine white; dorsal XII, 22 or 23, 

 anal III, 18 or 19; scale rows about 50 to 53. 



Heniochus perniutatus Cuvier 

 66. A blackish band from origin of dorsal extending downward and 

 covering front part of head orbits, chin, and muzzle, leaving 

 lips and a triangular patch in front of orbits white; a second 

 transverse band extending from fifth to seventh dorsal spine, 

 getting broader while descending to belly, and reaching from 

 origin of pelvics to vent ; a third blackish band, narrower and 

 less defined, descending from hind part of spinous dorsal 

 to posterior half of soft anal; interorbital space white, but 

 the supraorbital space more blackish ; pectorals plain, base 

 black; caudal fin pale; margin of anal fin black including spines 

 and the posterior half of fin black including spines; soft dorsal 

 pale; dorsal rays XII, 25 or 26; anal III, 18 or 19; scale rows 



56 to 58 Heniochus monoceros (Cuvier) 



36. None of dorsal spines prolonged, fourth and fifth not especially longer 

 than other spines; no bony prominences on nape or over eyes. 

 7a. Dorsal rays XIV, 15 to 17; anal IV (seldom V), 15 or 16; soft 



