FISHES. 469 



on the sides, and the black spot on the dorsal, always 

 present. Attains a large size here, a perch of 5 Ib. 

 not being uncommon ; spawns in May ; frequents brack- 

 ish as well as fresh waters. 



Fin May Formula. 



D. 151,14; P. 14; Y. 1,5; A. 2,8; C. 17.* 

 The fin ray formula in all fish is subject to much variation, 

 and can never be closely relied upon as a mark of distinction. 



Gen. Labrax, Cuv. 



Opercle scaled, with two spines ; teeth on the tongue ; 

 sea-fish. 



2. P. LABEAX, Cuv. Hafs Abborre. The Basse. D. 



Sides silvery, without transverse bands ; no spot on 

 the dorsal ; body longer, and back not so high, as in 

 the perch. The largest example recorded to have been 

 taken in these seas was 13 J in. long, and weighed 1^ Ib. 

 Their usual size in more southern seas is 18 in., but 

 they often reach 2 ft. and over. D. 91,12; P. 16; 

 B.1,5; A. 3,11; C. 17. 

 Is a very rare fish in these seas, and has hitherto only 



been accidentally taken off the southern coast of Norway, 



and once in the Sound. 



Gen: Lucioperca, Cuv. 



Body elongated, more resembling the pike than the 

 perch ; opercle without spines ; preopercle serrated ; teeth on 

 the vomer ; sides silvery white, with dark spots or trans- 

 verse bands. Fresh waters. 



3. LlJCIOPEKCA SANDRA, Cuv. GoS. D. F. 



Colour greenish brown ; sides silvery ; sides of the 

 back marked with ten to twelve transverse bands. 

 Common in many of the Swedish fresh waters, which are 



* The formulae for the fins of fish are explained thus : D. means dorsal 

 fin ; P., pectoral ; Y., ventral ; A., anal ; C., caudal ; Br., the small fin, or 

 fins sometimes attached to the bones of the operculum, or gill cover. The 

 numbers express the rays, spinous or soft, thus 15, means 15 hard rays ; 

 15,4, means 15 hard and 4 soft rays ; V. 3j5, means ventral, 3 hard and 5 

 soft rays. 



