REPORT ON ICHTHYOLOGY. 387 



is equivalent to Gobius of Linnsuus ; Asperulus to Aspro ot Cuvier ; and Triehidion to 

 Poli/nemus of Linnauis. 



The group, it will be thus seen, is composed of very dissimilar elements. Fi'om 

 it are also excluded Perca, and other genera with the dorsal fins quite as distinct. The 

 Perches are placed in a group of which the character is the presence of only one 

 dorsal entire or siiuiate. 



Lahrax itself is defined* as having as many fins as Ccstrccus (or JMiuj'd Linn.) ; 

 serrated scales ; the mouth large, and provided with numerous slender teeth in many 

 rows. Two species are referred to it : the Lahrax diacanthus Gill {Sciccna diacantha 

 Blocli, Lahrax liqnis Linn.) ; and the Centropomus undecimalis of Lacepfede, and the 

 moderns. The genus itself is therefore not very unnatural, hut its characters are 

 common to many others, especially to Perca. 



In the second and third volumes of the great " Histoire Naturelle des Poissons ", 

 Cuvier and Valenciennes have referred to the genus Lahrax seven nominal species, six 

 of wliich are described in the former volume. 



Of these, the Lahrax hqncs is the type of the genus, and is distinguished by the 

 spur-like spines of the inferior margin of the preopercalum ; the presence of a perfect 

 marginal band of teeth, and of an oval basal patch on the tongue ; tlu-ee spines to the 

 anal fin ; and other characters, which have been noticed in the preceding synopsis. 

 To this should the name Lahrax be restricted. 



The second species (le Bar alonge, or Perca cknifjuta of Geoffroy) is distinguished 

 by finer and more numerous teeth on the inferior border of the preoperculum, and the 

 presence of only two anal spines. The distinctive characters of this species, however, 

 require to be confirmed. 



The third species is the Lahrax Imeatus of Cuvier, the common Rock-fish or Striped 

 Bass of the United States. This has been taken as the type of a new genus, for which 

 Mitchill's name Rocciis is preserved. The characters are given below. To this genus 

 should be also referred the Lahrax multilineatus described by Cuvier and Valenciennes 

 in the third volnine of their "Histoire Naturelle des Poissons". 



The fourth species, Lahrax Walgiensis, has been identified by Bleeker with the 

 Psammoperca datuioidcs of Richardson; if this is correct (and, notwithstanding the dis- 

 crepancies between the descriptions of the "Histoire Naturelle" and Richardson, such 

 appears to be the case), it belongs to a very distinct genus from the Lahrax lupus. The 

 teeth of the jaws, vomer, and j^alatines are described by Richardson as crowded, rounded, 

 and gramdar, 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 disk at the base of the tongue ; by Richardson, the tongue is 

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

 and Valenciennes, but with Bleeker, who also assertsf that there is an oblong patch at 

 the base of the tongue, "lingua basi thunna denticulorum scabra." Both authors agree 

 as to the presence of a single spine to the operculum (although one of the generic 

 characters assigned to Lahrax by Cuvier was the presence of two spines on that bbne), 



•Pinnas habct tot quot Ccstra-us et Mugil: squamas semitas: 08 magnum plurimis tenuissimisque dentibus 

 multiplici ordino inunitum. Voracissimna. 



t Natiuirkiiiidig Tydsclirift voor Nederlandnch Indie, vol. ii, p. 4711. 



