ACANTIIOPTERYGII. 107 



Polyp, cernium, Valcnc; Mem. du Mus. torn. XI, p. 265; and 

 Cuv. and Val., Ill, pi, xlii.(l) An enormous species found in 

 the Mediterranean; it is clouded with brown on a lighter 

 ground. 



Centropristis, CtlV. 



All the characters of Serranus except that there are no canini, 

 and that all the teeth are small and crowded; preoperculum dentated 

 and operculum spinous. 



Centrop. nigricans, Cuv.; Coryphxna nigrescens, Bl., Schn.; 



Cuv. and Val., Ill, pi. xliv. (The Black Perch.) Blackish brown; 



the caudal fin trilobate when young. It becomes large, and is 



found in the United States.(2) 



Gristes, CtlV. 



Only differs from Centropristis in the margin of the preopercu- 

 lum, Avhich is entire and not dentated. (3) 



The genus Perca, as defined by Artedi and Linnaaus, ter- 

 minates here ; but there remains a number of fishes which ap- 

 proach itj although peculiar characters compel us to arrange 

 them in separate genera. 



We will begin with those Percoides which have less than 

 seven branchial rays. We may also subdivide them according 

 to the number of their dorsals, and the nature of their teeth. 



Of those with a single dorsal, some have hooked teeth among 

 the others : they are the 



CiRRHiTES, Comraers. 



Preoperculum, as in Mesoprion, dentated, and the operculum termi- 

 nating in an obtuse angle; distinguished by the inferior rays of the 

 pectoral, which are stouter and not branched, that extend a little be- 



(1) The Amphiprion australis, Bl., Schn., pi. 47, or americanus, lb., p. 205; and 

 the Amph. oxygeneios, lb., or Ferca prognathus, Forst. do not appear to us distin. 

 guishable from the cemium. 



(2) It is also the Lufjan triloba, I.acep. II, xvi, 3, and the Perca varla, Mitchill, 

 Trans. New York, I. Add Perca trifurca, L. ; La Scorpene de Waigiou, Quoy et 

 Gaym. Freycin., Zool., LVIII, 1; and the other species described in the third 

 Vol. of our History of Fishes. 



(3) The Labre salmo't'de, L.Sicei). IV, v, 2, or Cychla variabilis, Lesueur, Ac. 

 Nat. Sc. Phil., Cuv., et Val., Ill, pi. xlv; Gr. matquariensis, lb., p. 58. 



