ACANTHOPTERYGIANS. 85 



rally hard or rough, and whose operculum or preoperculum, and fre- 

 quently both, have dentated or spinous edges, and whose jaws, the fore- 

 part of the vomer, and almost always the palatine bones, are furnished 

 with teeth. 



The species are extremely numerous, particularly in the seas of hot 

 climates ; their flesh is generally wholesome and agreeable. 



In a vast proportion of these Perches, the ventral fins are inserted 

 under the pectorals: they form a first division, which may be called Per- 

 coides Thoracici, or Thoracic Perches. 



They were nearly all comprised by Linnaaus in his genus Perca, but 

 we have been compelled to divide them as follows, from the number of 

 the branchial rays, that of the dorsal fin, and the nature of the teeth. 



The first subdivision has seven rays in the branchiae, two fins on the 

 back, and all the teeth small and dense as the pile on velvet. 



Perca, Cuv. 



The true Perches have the preoperculum dentated: the bony opercu- 

 lum terminated by two or three sharp points and a smooth tongue. Some- 

 times the sub-orbital and the humeral are slightly dentated. 



P. fluvialis, L. ; Bl. 52. (The Common Perch). Greenish; 

 broad, vertical, blackish bands; ventral and anal fins red; one of the 

 most beautiful and best of the European fresh-water fishes. It in- 

 habits pure and running streams ; its eggs are united by a viscid 

 matter into long strings, which form a kind of net-work. 



North America produces several neighbouring species*. 



Labrax, Cuv. 



The Bars are distinguished from the Perches by scaly opercula termi- 

 nating in two spines, and by a rough tongue. 



L. lupus, Cuv. ; Perca labrax, L. ; Sc. diacantha, Bloch, 305 ; 

 Bars Commun ; Spigola of the Italians; Cuv. and Val. II, xi. 

 (The Basse Perch). A large fish found on the coast of Europe ; it 

 is highly flavoured, and of a silvery hue. It is particularly common 

 in the Mediterranean, and is the Lupus of the Romans, and the 

 Labrax of the Greeks. The young ones are usually spotted with 

 brown. 



The United States produce a large and beautiful species, Lahr. 

 lineatus, Cuv., Selena lineata, Bloch, 304, and Perca saxatilis] 



from it, and I think I have been fortunate enough to discover sufficient characters 

 for that purpose. 



* Pern, flavescens, Cuv. and Val. II, p. 46; — P. serrato-gramdata, lb. 47;— P. gra* 

 nulata, lb. 48, and pi. ix; — P. acuta, lb. 49, and pi. x; — P. gracilis, lb. 50. 



Add, P. Plumieri, or Scitena Plumieri, Bl. 306, or Centropome Plumier and Cltcilo- 

 diplrrc chrysoptire, Lacep. Ill, xxxiii; — P. ci/iata, Kuhl; — P. marginata, Cuv. and 

 Val. 515. 



