NATURAL SCIENCES OF PHILADELPHIA. 109 



the spur-like spines of the inferior margin of the preoperculum ; the presence 

 of a perfect marginal band of teeth and of an oval basal patch on the tongue ; 

 three spines to the anal fin. and other characters which will be noticed in the 

 diagnosis of the genus. To this should the name of Labrax be restricted. 



The second species (le Bar alonge, or Perca elongata of Geoffrey) is distin- 

 guished by finer and more numerous teeth on the inferior border of the preoper- 

 culum, and the presence of only two anal spines. This is doubtless the type of 

 a distinct genus to which the name of Dicentrarchus may be given. 



The third species is the Labrax lineatus of Cuvier, the common rock fish 

 and striped bass of the United States. This is now taken as the type of a new 

 genus, for which Mitchell's name of Roccua is preserved. The characters are 

 given below. To this genus should be also referred the Labrax multiline- 

 atus described by Cuvier and Valenciennes in the third volume of their 

 "Histoire." 



The fourth species, Labrax Waigiensis, has been identified by Bleeker 

 with the Psammoperca datnioides of Richardson; if this is correct, and 

 notwithstanding the discrepancies between the descriptions of the "Histoire 

 Naturelle" and Richardson, such appears to be the case it belongs to a very 

 distinct genus from Labrax 1 u pu s . The teeth of the jaws, vomer and palatines 

 are described by Richardson as crowded, rounded and granular, while by Cuvier 

 the teeth on both jaws, the chevron of the vomer and the palatines are said to be 

 villiform (" dents en velours "); it is also stated by Cuvier that there is a small 

 oval disc at the base of the tongue. By Richardson, the tongue is said to be 

 smooth. In the latter statement, however, be disagrees not only with Cuvier 

 and Valenciennes, but with Bleeker, who also asserts* that there is an oblong 

 patch at the base of the tongue; " lingua basi thurma denticulorum scabra." 

 Both authors agree as to the presence of a single spine to the operculum 

 (although one of the generic characters assigned to Labrax by Cuvier is the 

 presence of two spines on that bone), and of a strong horizontal spine at the 

 angle of the preoperculum, above which the margin is pectinated. 



The next species in order, Labrax Japonic us of Cuv. and Val., is the 

 type of the genus Lateolabrax of Bleeker, which is widely separated from 

 Labrax by the absence of any teeth on the tongue. In the plectroid armature 

 of the operculum it, however, resembles that genus. 



The last species Labrax mucronatu s is now taken as the type of a new 

 genus, for which the name of Morone is accepted. Its generic characters and 

 affinities will be given at length in a subsequent portion of this memoir. 



Of the seven species referred by Cuvier and Valenciennes to the genus Labrax, 

 six are thus seen to belong to different genera. Nor do any of these genera 

 appear to be unnecessary, but on the contrary, all of them are well distinguished 

 from each other by characters that ichthyologists must admit are of importance ; 

 two of the species, indeed, that were referred to the genus by the French nat- 

 uralists, do not agree with their characters of that genus. It is not in dispar- 

 agement of those celebrated and able men that these remarks have been made. 

 The progress of scientific discovery and the examination of better materials 

 have enabled their successors to discover the errors of the founders of modern 

 ichthyology. None could have performed the work at that day better than they. 

 Having long since, from an examination of the descriptions of various 

 authors, been aware of the confusion and uncertainty in which our American 

 species of the Cuvieran Labrax were enveloped, I have thought that it might be 

 a useful task to attempt the elucidation of the genus. More than three years 

 ago, I had noticed that the Labrax rufus of Dekay belonged to a different 

 natural genus from Labrax, but not having then had an opportunity of exam- 

 ining the European species, I believed that the Labrax lineatus was a true 

 Labrax. The name which I had then applied to the Labrax rufus having 

 never been published, I have now renounced it for that of Mitchell, not b :^use 



* Natuurkundig Tydschrift voor Nederlandsch Indie, vol. ii. p. 479. 



I860.] 



