338 ACRONtJKID^. 



lines. 



Total length 60 



Height of the body 23 



Length of the head 13 



of the caudal fin 11 



of the last dorsal spine 8 



24. Acanthurus gahm. 



Chsetodon gahhni, Forsk. p. 64. 



Acanthurus gahm, Cuv. Sr Val. x. p. 219 ; Hiipp. Atl. Fische, p. 58, 



and N. W. Fische, p. 131 ; Bleek. Act. Soc. Sc. Indo-Nederl. iii., 



Celebes, p. 8. 



T) A A ^ 

 "' 27- ^- ii- 



The height of the body is one-third or rather less than one-third 

 of the total length (the caudal fin included), the length of the head 

 one-sixth ; there are sixteen or twenty teeth in each of the jaws, 

 denticulated on the free half. The profile of the snout is convex. 

 The height of the dorsal and anal fins is about one-thii'd of that of 

 the body ; the length of the pectoral is one-fifth of the total, that of 

 the ventral one-sixth ; caudal with the middle somewhat convex, 

 and with the lobes much produced, the latter being two-sevenths of 

 the total length. Brown : a whitish spot before the orbit ; the 

 suprascapular region orange-coloured, with a black streak from the 

 opercle to above the middle of the pectoral fin ; another black band 

 from the caudal spine to above the middle of the anal. A white band 

 across the base of the caudal, which has a white margin, and another 

 blackish band within the margin. Pectoral whitish at the base, 

 brownish on the middle, and yellowish at the margin. 



Red Sea. Mauritius. Celebes. 



25. Acanthurus nummifer. 



Acanthiu'us bariene. Less. Voy. Coq. Zool. p. 150. 

 nummifer, Cuv. 8f Val. x. p. 234. 



T) 9 A 3 



The height of the body is more than one-half of the length (the 

 caudal fin not racluded) ; the upper profile of the head arched, and' 

 prominent beyond the mouth, which is entirely situated at the lower 

 side of the head. Head covered entirely with scales, which are much 

 smaller than those on the body ; mouth and shoulder naked ; sixteen 

 to twenty crenulated teeth in each of the jaws; ventral fins produced 

 into a point ; the first spine of the dorsal fin is entii'ely hidden below 

 the skin. Dark bro^wTi, with a roimd bhiish-black spot superiorly 

 at the gill-opening ; sheath of the caudal spine black. A light- 

 blue line along the base of the dorsal and anal fins ; the margin of 

 the dorsal with two or three violet lines; anal blue-edged. {Val.) 



Waigiou. 



The typical specimen is one foot long. 



