PISHES 



121 



M. dolomieu Lac. Small-mouthed black bass. Length 600 mm.; 

 head 2.5 to 3.5; depth t,.t,] color a uniform dull green, with a golden 

 lustre; 3 longitudinal bands of the head back of the eye; young with dark 

 spots; rays of dorsal fin X, 13 to 15; anal III, 10 to 12; scales 11-72 to 

 78-25: Lake Champlain to Manitoba; southward to South Carolina 

 and Arkansas; common, especially in clear, cool streams and lakes; 

 introduced into New England and many other places. 



M. salmoides (Lac.) . Large-mouthed black bass. Length 750 mm. ; 

 extreme weight 20 lbs.; head 3 to 3.5; depth 3 to 3.25; color dark green, 

 silvery below; adult plain, young with a broad blackish lateral band; 



\^^. 



Fig. 54. — Black bass heads: a, head of Micropterus dolomieu; b, head of M. salmoides 



(from Jordan &= Evennann). 



3 longitudinal bands on the head back of the eye; rays of dorsal fin X, 

 12 to 13; anal III, 10 or 11; scales 7-65 to 70-18: Great Lakes region to 

 Dakota; southward to Florida and Mexico; common, especially in 

 lakes and sluggish waters. 



4. Family Percidae. — The perch and darters. Body elongate or 

 elliptical; scales ctenoid and small; lateral line usually present; mouth 

 terminal or inferior; opercle usually ending in a flat spine; branch- 

 iostegals 6 or 7; 2 dorsal fins, anterior with 6 to 16 spines; anal fin with i 

 or 2 spines; ventral fins thoracic, with rays I, 5; air bladder small, often 

 wanting; pyloric caeca few: about 23 genera and 1 20 species, inhabiting 

 the fresh waters of the northern hemisphere. 



Key to the United States Genera of the Percidae 



ai Pseud obranchiae well developed; branchiostegals 7. 

 bi Ventral fins close together; Subfamily i. Percince. 

 bo Ventral fins separated by a 



space; Subfamily 2. LuciopercincB 



a.2 Pseudobranchias imperfect or wanting; branchio- 

 stegals 6; small, often diminutive, fishes, exclu- 

 sively American ; Subfamily 2,- Etheostomince. 



I. Perca. 



Stizostedion. 



