112 PROCEEDINGS OP THE ACADEMY OF 



The genu3 Roccus is very closely allied to both Labrax, as here revised, and 

 Morone. From Labrax it differs chiefly in the character of the armature of the 

 preoperculum, and by the absence of the teeth at the anterior extremity of the 

 tongue; the whole margin of the tongue in the latter genus being provided 

 with a band of villiform teeth, and the spur-formed teeth of the inferior margin 

 of the preoperculum calling to mind the genus Plectropoma of Cuvier among the 

 Serrani. The difference between the last named genus or at least of many of 

 its species and Serranus is indeed not of as great value as that between Labrax 

 and Roccus. The only constant character between Serranus and Plectropoma, as 

 those genera were established by Cuvier, is the spur-like dentition of the 

 inferior border of the preoperculum, while Labrax and Roccus are distinguished 

 not only by an equally great and constant difference of the preopercular border, 

 but also by the difference of the lingual dentition. As the former character is 

 of as great value in the Labraces as in the Serrani, consistency will require that 

 if Plectropoma and Serranus are considered as distinct genera, Roccus and Labrax 

 should also be so regarded. 



The difference between Roccus and Morone is of even more importance than 

 that of Roccus and Labrax. The distinguishing characters will be referred to 

 under the diagnosis of Morone. 



The name which has been adopted for this genus is one given by Dr. Mitchell, 

 in the year 1814, to a medley comprising the Roccus lineatus, which he 

 called Roccus s tr i at u s , and the Otolithus re gal is, which was designated 

 as Roccus comes. The name was solely the result of ignorance on the part 

 of the author, of the application of the ordinary terms used by naturalists at 

 that day. The name itself is a barbarous latinization of the popular name, 

 rock fish, by which its chief species is known in many parts of the United 

 States. Notwithstanding these facts, it has been nevertheless deemed more 

 advisable to accept the name than to apply a new one. It is scarcely worse 

 than Raltus, Kangurus, Catus, Gunnellus, and many other names of similar 

 derivation. 



Rafinesque, in the " Ichthyologia Ohiensis," also proposed for his Perca 

 chrysops, in case it should be found to be generically distinct from Perca, 

 the name of Lepibema. He believed it to be distinguished " by the scaly bases 

 of the caudal, anal and second dorsal fins, the last with some spiny rays, and 

 all the three parts of the gill cover more or less serrulate, besides the small 

 teeth." Rafinesque suggested that to this genus the Perca Mite belli of 

 Mitchell might " perhaps be found to belong." 



The genus Roccus may be divided into two sections. 



1. Corpus elongatum; dentes ad lingua? basin in seriebus longitudinalibus 

 duabus ordinati. 



Roccus lineatus Gill. 



Synonymy. 



Sciaina lineata Bloch, Ichthyologie, pars. ix. p. 53, pi. 305. 



Perca Schoepff., Schrift. der Gesells. Nat. Freund, vol. viii. p. 160. 



Perca saxatilis Bloch, Systema Ichthyologia?, Schneid. ed. p. 89. 



Perca septentrionalis Bloch, Systema Ichthyologise, Schneid. ed. p. 90, pi. 70. 



Centropome raye Lac, Hist. Nat. des Poissons, vol. iv. p. 225. 



Roccus striatus Mitchell, Report in part on the fishes of New York, p. 25, 1814. 



Perca Mitchelli Mitchell. Trans. Lit. and Phil. Soc, N. Y., vol. i. p. 413, pi. 3 



fig. 4. 

 Rock-Fish Mease, Trans. Lit and Phil. Soc, N. Y., vol. i. p. 502. 



Perca, Mitchelli l Raf Ichthiologia Ohiensis, p. 23, (passim). 

 Lepibema Mitchelli ) i r j vr 



Labrax lineatus Cuv. et Val., Hist. Nat. des Poissons, vol. ii. p. 79. 

 Perca labrax! Smith, Nat. Hist. Fishes of Mass., p. 277. 



[April, 



