1897.] NATURAL SCIENCES OF PHILADELPHIA. 125 



ish-green ; chin and narrow line around upper jaw white, end of 

 both jaws very dark. 



157. Poinacanthus arcuatus (Linnaeus). 



Chcrtodon arcuatus Linnseus, Syst. Nat., Ed. X, 273, 1758 (Indies). 

 Pomocanthus arcuatus, Eigenmann & Horning, Chjetodontidae, 13. 



The young of this species has the tip of the caudal white and the 

 base of the pectoral but slightly yellow. This species is distin- 

 guished from Poinacanthus paru by its rounded caudal besides other 

 characters, the latter having the caudal truncate. 



158. Holacanthus tricolor (Bloch). Rock Beauty. 



Chcrtodon tricolor Bloch, Ichth., pi. 426, 1795. 



Potnocanthus tricolor, Eigenmann & Horning, Review of Chretodontidae, 15. 



Head and body in front of a line connecting second dorsal spine, 

 axil of pectoral and second anal spine, lemon -yellow, slightly orange 

 in front of dorsal ; pectorals and ventrals lemon-yellow ; the caudal 

 similar but thickly covered with reddish-orange dots ; remaining 

 part of body, vertical fins and lips black ; slightly dusky between 

 eyes ; horizontal margins of vertical fins, margin of opercle and pre- 

 opercular spine reddish ; posterior tips of dorsal and anal lemon- 

 yellow ; iris yellow-blue above and below. 



159. Angelichthys ciliaris (Linnanis). Angel Fish. 



Clnetodon ciliaris Linnasus, Syst. Nat., Ed. X, 276, 1758 (Indies). 



Head Bi, depth If, eye 4* in head ; dorsal XIV, 21 ; anal III, 

 21. 



Body oblong, oval ; anterior profile straight, steep, sharply con- 

 vex in front of dorsal ; anterior dorsal outline and ventral outline 

 nearly parallel ; jaws projecting. Length of head equal to its 

 depth from anterior margin of blue ring in front of dorsal. Snout 

 2 § in head, the preorbital one-third broader than eye, with one or 

 two indistinct spines. Preopercle with a strong grooved, lightly 

 curved spine at angle, about as long as orbit ; five or six short, blunt 

 spines with intermediate minute ones on upper limb, the longest of 

 these" spines 6 in the spine at the angle ; two or three short, strong 

 spines on lower limb. Interopercle with one or two short spines. 

 Premaxillary very thick, its width above equal to orbit. A furrow 

 from front of eye below nostrils. Interorbital greater than preor- 

 bital, equal to distance between eye and upper end of gill-opening. 

 Soft dorsal and anal falcate, the filamentous tips reaching much be- 

 yond the caudal. Pectoral broad, obliquely rounded, II in head. Ven- 



