CLASS PISCES. 117 



The Mediterranean possesses a species which be- 

 comes enormous, and is shaded with brown on a 

 lighter ground, (Polyprion cernium, Valenc,) Mem. du 

 Mus. t. xi. p. 265. Cuv. and Val. iii. pi. xlii l . 



Centropristris, Cuv. 



Have all the characters of serrani, except that they are 

 destitute of canine teeth, and have all their teeth even. 

 Their preoperculum is denticulated and the operculum 

 spinous. 



The United States have one which becomes large, 

 and in which the caudal fin when young is trilobate. 

 It is their black perch, {Centropristris nigricans, Cuv.) 

 Coryphcena fiigrescens, Bl. Sch., Cuv. and Val. iii. 

 pi. xliv. It is blackish brown 2 . 



Grystes, Cuv. 



Differ from the last only in having the preoperculum 

 entire and not denticulated at the edges 3 . 



The genus Perca terminates here, such as it has 



1 Am. australis, Bl. Schn. pi. xlvii., or Americanus, ib. p. 205., 

 and Am. oxijgeneios, ib., or Perca prognathus, Forst., do not appear 

 to us distinguishable from the P. cernium. 



2 It is also the Lutjan trilobe, Lacep. II. xvi. 3., and the Perca 

 varia, Mitchill, New York Trans. Add Perca trifurca, L. Scorpene 

 de JVaigiou, Quoy. andGaym , Freycin. Zool. 58. 1., and the other 

 species described in our third volume of the history of Fish. 



3 Labre salmo'ide, Lacep. IV. v. 2., or Cychla variabilis, Lesueur, 

 Sc. Nat. Phil., Cuv. and Val. iii. pi. xlv. Gr. Macquariensis, ib. 

 p. 58. 



