NATURAL SCIENCES OF PHILADELPHIA. 49 



Genus Labrax Klein, Gill. 



Labrax sp. Klein, Historian Piscium prornovendae Missus quintus et ultinaus, 



p. 25. 

 Labrax sp. Cuv., Regne Animal, ed. i. vol. ii. 

 Labrax Gill, Proceedings of Academy of Natural Sciences of Philada., 1860, 



p. 111. 



Body elongated and subfusiform. Head conical in profile, mostly covered 

 with cycloid scales. Tongue furnished with teeth arranged in a marginal 

 band and in an oval patch at its .base. Preoperculum posteriorly serrated, 

 below armed with spines directed forwards. Operculum with two spines. 

 Suborbital bone entire. Dorsal fins disconnected ; the first supported by 

 nine spines. Anal fin with three spines and about ten branched rays. 



There is only a single species of the genus Labrax, as that genus has re- 

 cently been restricted ; it is found in the Mediterranean Sea and along the 

 western coasts of Europe. 



Type. Labrax diacanthus Gill. 

 Syn. Labrax lupus Cuv. et Vol., auct. 



Genus Dicentrarchus Gill. 

 Perca sp. Geoffrey. 

 Labrax sp. Cuv. et Val. 



Dicentrarchus Gill, Proceedings of Academy of Natural Sciences of Philada., 

 1860, p. 111. 



This genus has been separated from the preceding on account of the 

 presence of only two spines in the anal fin, and the smaller and less recurved 

 teeth of the inferior margin of the preoperculum. 



Only one species is known ; it has only been taken in the Mediterranean 

 Sea. 



Type. Dicentrarchus elongatus Gill. 

 Syn. Labrax elongata Cuv. et Val. 



Genus Roccus Gill. 

 Roccus Mitchill. 

 Lepibema sp. Rafinesque. 



Roccus Gill, Proceedings of Academy of Natural Sciences of Philada., p. 

 111. 



Head conical in profile ; cheeks covered with cycloid scales. Tongue pro- 

 vided with a band of villiform teeth on each side and in a single or divided 

 patch at its base. Preoperculum posteriorly pectinated, below serrated. 

 Operculum armed with two spines. Suborbital bones entire. Dorsal fins not 

 united by the membrane ; the anterior with nine spines. Anal fin furnished 

 with three spines and from eleven to fourteen branched rays. 



Subgenus Roccus Gill. 



Body elongated and subfusiform. Teeth on the base of the tongue arranged 

 in longitudinal patches. 



The only known species is the common "rock fish " or " striped bass " of 

 the Americans ; it dwells in the sea, and ascends the fresh water streams to 

 spawn. 



Type. Roccus lineatus Gill. 

 Syn. Labrax lineatus Cuv. et Val. 



Subgenus Lepibema Gill. 



Body oblong-ovate and compressed. Teeth crowded at the base in a single 

 oval patch. 



1861.] 4 



