330 PISCES. [PERCA. 



(I. OSSEI.) 



ORDER I. ACANTHOPTERYGII. 



GEN. 1. PERCA, Linn. 



(1. PERCA, Cuv.) 



1. P. Jluviatilis, Linn. (Common Perch.) Back 

 dusky green ; sides with five transverse dusky bands. 



P. fluviatilis, Linn. Syst. Nat. torn. i. p. 481. Block, Ichth. pi. 52. 

 Don. Brit. Fish. vol. in. pi. 52. Flem. Brit. An. p. 213. Perch, 

 Witt. Hist. Pise. p. 291. tab. S. 13. f. 1. Penn. Brit. Zool. vol. in. 

 p. 254. pi. 48. no. 124. Id. (Edit. 1812.) vol. in. p. 345. pi. 59. 

 Bowd. Brit. fr. wat. Fish. Draw. 5. Yarr. Brit. Fish. vol. i. 

 p. 1. Perche commune, Cuv. et Vol. Poiss. torn. n. p. 14. 

 Cuv. Reg. An. torn. n. p. 132. 



LENGTH. From twelve to sixteen inches. 



DESCRIPT. (Form.) Body compressed; back much arched, highest 

 over the ventrals, the depth at that part equalling nearly one-third of 

 the length, caudal fin excluded ; greatest thickness half the depth : head 

 about one-fourth of the entire length, including caudal : nape depressed, 

 the back rising rather suddenly behind ; profile gently falling from the 

 forehead towards the end of the snout: jaws nearly equal; teeth in both 

 jaws, as well as on the vomer, palatines, pharyngeans, and branchial 

 arches : head and cheeks for the most part smooth, the latter covered 

 with small scales: preopercle rectangular; the margin finely serrated: 

 opercle triangular, terminating behind in a sharp point ; the subopercle 

 reaching beyond it : gill-opening large : lateral line nearly parallel with 

 the line of the back, its course at about one-fourth of the depth*: first 

 dorsal fin commencing in a line with the terminating point of the oper- 

 cle ; the fourth and fifth rays longest ; those on each side gradually de- 

 creasing ; the last, or last two, in the fin small and inconspicuous ; height 

 of the longest rays nearly equalling half the depth of the body : second 



* The course of the lateral line is said to be at half, one-third, one-fourth, <fcc. of the depth, 

 when the distance from the line of the hack to the lateral line equals half, one-third, one-fourth, 

 \-c. of the depth of the hody. 



