358 PERCID^. 



operculum, and on the hinder prolongation of the operculum a 

 black spot with a bright scarlet margin. 



Its body is much compressed, very broad, oval. Scales large 

 and even. Forehead sloping to the snout. Lateral line con- 

 current with the back. Eyes large, cij'cular near the facial 

 outline. Nostrils double ; mouth small, with very minute thick- 

 set teeth on the maxillaries, palatines and vomer. 



Its dorsal fin has ten spinous, and twelve soft rays ; pectorals, 

 twelve soft; ventrals, one spine and five soft rays; anal, three 

 spinous and five soft; caudal, seventeen soft rays. 



There is another well-defined species, the Black-eared Pond- 

 fish {Pomotis Appendix), which is distinguished by a large lobe- 

 like black prolongation of the upper posterior angle of the 

 ope7'Culum. 



