CHiETODONID^. 211 



Family 2. CH^TODONID^. 



Operculum without prickles ; preopercule generally 

 smooth ; the spinal rays of the dorsal fewer than the 

 flexible rays ; dorsal fins generally united into one ; 

 scales and mouth small. 



1. SuBFAM. CH^TODONIN^. 



Body short_, broad^ much compressed; dorsal^ anal^ 

 and caudal fins thickly covered with minute scales * ; 

 teeth setaceous^ very slender_, rather long, crowded; 

 mouth remarkably small ; dorsal fin generally single ; 

 pectoral pointed^ sometimes emarginate. 



Ch^todon Linn. Body oval^ broad; mouth more or 

 less pointed ; no spine on the preoperculum^ or 

 prickles before the dorsal ; caudal truncate ; pectoral 

 fins small or moderate ; dorsal fin single. 



Rahdophorus Sw. Dorsal fin single^ but with the first 

 soft rays falcate^ and lengthened into a filament; 

 mouth porrectj and the lower jaw longest : repre- 

 senting Pomacanthus. 



Ephippium Sw. Cuv. pi. 174. 



ChcBtodon Linn. Dorsal single^ emarginate_, and rounded 

 behind ; all the rays gTaduated : representing Holo- 

 canthus. 



reticulatus. Cuv. pi. 171. 



Heniochus Cuv. An emarginate division between the 

 spinal and the soft rays of the dorsal; the fourth 

 ray more or less prolonged ; crown with horn-like 

 appendages ; ventral fins very large^ rounded^ equal 

 or longer than the pectorals, 

 monoceros. Cuv. pi. 176. taurichthys Sw. Cuv. pi. 181. 



Ckelmon Cuv. Mouth prolonged into a slender snout 

 or tube ; dorsal spines long, connected only at their 



* Except in Scatophagus, which seems to unite this genus with Gerres. 



p 2 



