ACANTHOPTERYGII. 201 



as the preceding ones, as by their teeth which are either hooked or 

 all small and crowded; notches and spines on the opercula, &c. 

 In the subdivision, furnished with hooked teeth, we find, 



Serranus, Cuv. 

 Preoperculum dentate; the bony operculum terminating in one or several 

 points. This genus contains a vast number of species, and is divided into 

 several subgenera. 



We now pass to Percoides with seven branchial rays, and a sin- 

 gle dorsal, the teeth small and crowded. 



They are distributed under the genera Acerina, Rypticus, Ceniroprisiis 

 (to which belongs our Black Perch) and Grisies. 



The genus Perca, as defined by Artedi and Linnaeus, terminates 

 here; but there remains a number of fishes which approach it, al- 

 though peculiar characters compel naturalists to arrange them in 

 separate genera, such as Cirrhites, Chironemus, Pomofw, (our Pond- 

 Perch) Centrarchusy &.c. &.c. 



PoMOTis, Cuv, 

 Fishes, with a compressed and oval body, characterized by a membranous 

 prolongation at the angle of the operculum. They inhabit the rivers, &c. 

 of America, where they are called Pond-Perch. 



We now pass to those Percoides which have more than seven 

 rays to the branchiag. Three genera are known, all of which pre- 

 sent the following peculiarity: their ventrals have a spine and seven 

 or more soft rays, while in other Acanthopterygii there are never 

 more than five soft rays. 



HoLOCENTRTiM, Artedi, 

 The scales of these beautiful fishes are brilliant and dentated; operculum 

 dentated and spinous; preoperculum dentated with a stout spine at the an- 

 gle, which is directed backwards. They are found in the hot parts of both 

 oceans. 



Mybipristis, Cuv. 



The brilliancy, shape and scales of the Holocentra, but the preoperculum 

 has a dentated double border, and there is no spine at the angle. They in- 

 habit the hot parts of both oceans. 

 2 A 



