48 PROCEEDINGS OP THE ACADEMY OP 



its true margin serrated posteriorly, and inferiorly armed generally with teeth 

 curved forwards. Operculum with a single spine. Suborbital bone entire. 

 Suprascapular, scapular and coracoid bones serrated. Dorsal fins entirely 

 disconnected ; the first provided with from twelve to fifteen spines. Anal fin 

 furnished with two spines. 



This genus, of which the common Yellow Perch is the type, is peculiar to 

 Europe and North America. Its species are not yet well defined or known. 



Type. Perca fluviatilis Linn. 



Genus Kdhlia Gill. 



Perca sp. Cuv. et Val., Hist. Nat. des Poissons, vol. ii. p. 52. 

 Percichthys sp. Giinther, Catalogue of the Acanthopterygian Fish. &c, vol. i. 

 p. 62. ' 



Body elongated, fusiform. Head conical. Anterior dorsal fin sustained by 

 nine spines ; the posterior with a spine and about eleven articulated rays. 



A single species is known ; it is peculiar, so far as known, to the Island of 

 Java. 



Type. Kuhlia ciliata Gill. 

 Syn. Perca ciliata Cuv. et Val. 



Genus Niphon Cuv. et Val. 



Niphon Cuv. et Val., Hist. Nat. des Poissons, vol. ii. p. 131. 



Body elongated and subfusiform. Head oblong-conical in profile. Lower 

 jaw longer. Preoperculum posteriorly serrated, armed below with anteriorly 

 recurved spines, and at the angle with a large horizontal one. Operculum 

 with three strong spines. Suborbital bone serrated. Dorsal fins connected at 

 the base by a little elevated membrane ; the anterior with twelve spines. 

 Anal fin with three moderate spines. A single species is found in the Chinese 

 and Japanese seas. 



Type. Niphon spinosus Cuv. el Val. 



* * 



Lateral line elevated and continued between the median rays to the margin 

 of the forked caudal fin. 



Genus Centropomus (Lac.) Cuv. 



Labrax sp. Klein. 



Centropomus sp. Lacepede, Hist. Nat. des Poissons, vol. iv. p. 248. 



Centropomus Cuv., Regne Animal, ed. i. vol. ii. 



Body elongated and fusiform. Head oblong-conical in profile. Lower jaw 

 longer. Preoperculum with the anterior margin furnished with two spines at 

 its angle, and with its posterior and inferior serrated and armed at the angle 

 with larger teeth directed backwards. Operculum with no true spine. Sub- 

 orbital and suprascapular bones serrated. Dorsal fins entirely disconnected ; 

 the first sustained by eight spines. Anal fin trapezoidal, with three spines, 

 the second of which is very large, and with about six branched rays. 



Several species are found in the Carribbean Sea, Gulf of Mexico, and along 

 the neighboring coasts. 



Type. Centropomus undecimalis Lac. 



b. 



Head with its dorsal surface covered with scales, extending almost to the 

 nostrils. Anterior dorsal fin furnished with from nine to eleven spines. 



b*. 



Teeth on the jaws and palate villiform ; tongue or interbranchial isthmus 

 with villiform teeth. 



[Feb. 



