ACANTHOPTERYGIANS. 87 



teetli small and dense as the pile on velvet; head depressed; the muzzle 

 extending beyond the mouth, and terminating in a rounded point. 



Two species inhabit the fresh waters of Europe ; their flesh is 

 delicate and agreeable. 



Aspro vulgaris, Cuv. ; Perca asper, L. ; Bl. 107, 1 and 2; Cuv. 

 and Val. II, xxvi. From the Rhone and its tributaries ; greenish ; 

 three or four blackish vertical bands; eight spines in the first 

 dorsal. 



A. Zlngel; Perca Zingel, L. ; Bl. 105. From the Danube; 

 larger than the vulgaris, but similar as to colours; thirteen spines in 

 the first dorsal. 

 This division also comprises some fishes whose singularity of con- 

 formation gives rise to several subgenera. 



Huro, Cuv. and Val. 



The Hurons have all the characters of a true Perch, except that the 

 preoperculum is not dentated*. 



Etelis, Cuv. and Val. 



All the characters of a true Perch : hooked teeth in the jaws, but not 

 as in the Lucio-Perca, in the palate f. 



Niphon, Cuv. and Val. 



Teeth as in the Perch, and strong spines at the lower part of the pre- 

 operculum, and on the operculum \. 



Enoplosus, Lacep., 



Have the characters of the Perches; angle of the preoperculum more 

 deeply dentate ; the body much compressed, and, together with the two 

 dorsals, of great vertical height §. 



Diploprion, Kuhl and Van Hasselt, 



Have all the characters of a Perch; body compressed; a double den- 

 tated border on the lower part of the preoperculum, and two spines on 

 the operculum ||. 



Apogon, Lacep. 



The Surmullets have the body short, furnished, as well as the opercula, 

 with large scales that are easily dislodged; the two dorsals very separate, 

 and a double dentated border on the preoperculum. They are small fishes, 

 and generally red. One of them, 



Ap. rex mullorum, Cuv. ; Mullus imberbis, L. ; commonly called 



* Huro nigricans, Cuv. and Val. II, pi. xvii. 



f Etelis carbtinculus, lb. pi. xviii. 



% Niphon spinosus, lb. XIX. 



§ Enoplosus armatus, lb. XX, or Chretodon armntus t J. White. 



|| Diploprion bijascialum, Cuv. and Val. II, xxi. 



