I02 Dircflor s Aiuiual Report. 



178. Chsetodon trifasciatis Quoy & Gaim. 



Head 3; depth 1.75; eye 3.50, i into snout; interorbital 2.75; 

 D. XIV 17; A. IV 16; V. I 5. Scales 9-37-14. Body moderately 

 elevated and stronglj' compressed. The snout rather sharp-pointed. 

 Lower edge of preopercle serrated. Branchiostegals 6. Teeth 

 setiform. The dorsal spines are of moderate strength, the longest 

 spine 1 .75 into head. Pedlorals and ventrals of about equal length, 

 1.60 into head. Color in spirits: Yellowish white, with about 15 

 rather indistinct oblique dusk}- lines, angularly bent, with the 

 angle direcfted forward. The black ocular baud edged with white 

 of about the same width as eye, extends from the neck to chest, 

 forming a complete ring. A black band, slightl}' wider than eye, 

 covers all the soft dorsal and extends down to posterior part of soft 

 anal; this band is anteriorly margined with white. The fins are 

 white, the caudal with a wash of yellow, a narrow^ black line near 

 the middle. Onh' one specimen, 2 inches in length, was taken. 

 Guam, July 14, 1900. This species is well figured in Freycinet, 

 "Voy. Uranie," Zool., PI. 62, Fig. 6. Hab. Polynesia, Marianas. 



Genus HBNIOCHUS Cuvier & Valenciennes. 



179-180. Heniochus chrysostoma (vSolander). 



Head 3; depth 1.40; D. xii 23; A. 11 18; eye 2.75. Scales 

 small, about 67 in the curved lateral line. Fins: Dorsal with fourth 

 spine elongated into a filament almost as long as depth of fish. 

 Pecftorals white, reaching to middle of black band on body. Ven- 

 trals black, reaching to base of anal. Caudal square, white with 

 dusk}' spot at base. Soft dorsal white, soft anal niostl}^ black. The 

 snout is short and sharp-pointed, mouth small, teeth villiform in 

 jaws. Color: Yellowish white, with three broad oblique bands of 

 black. The first black band extends from the front of orbit and 

 near fir,st dorsal spine, obliquely- down to base of ventral fins and 

 near to anus; the second black band extends from the 3-7 dorsal 

 spines to third and the last soft rays of anal; the third black band 

 extends from about the ninth dorsal spine along the base of soft 

 dorsal to the base of caudal. Snout dusk}-. Length 3.50 inches. 

 Several specimens were taken inside the coral reef, near Agana, 

 Guam, July, 1900. Hab. Indian Archipelago, Polynesia, Marianas. 



Family ^ANCI/ID^.— Moorish Idols. 



Genus ^ANCI/US Cuvier & Valenciennes. 



181-188. ^anclus canescens (Linn.). Ababang:. 

 Butterfly-fish. 



Head 2.45; depth about the same as length; eye 2.50 into snout; 

 D. vii 37; A. Ill 35. A frontal horn above each orbit in adult 

 specimens. Snout produced, teeth slender and brush-like, much 



