3i6 Field Museum of Natural History — Zoology, Vol. VII. 



Micropterus dolomieu Lacepede. Small-mouthed Black Bass. 



Head 2.9 to 3.7; depth 2.9 to 3.1; D. x, 13 to 15; A. in, 10 to 

 12; scales 66 to 78. 



Body elongate, moderately compressed, mouth large, the max- 

 illary not reaching posterior margin of orbit; its length 2»i to 2.5; 

 supplemental maxillary developed; eye 5.4 to 6.9 in head; snout 3.0 

 to 3.3; gill rakers long, spinous, dorsal low, its last spines much 

 shorter than the longest ones; pectorals short, 1.9 to 2.1 in head; lat- 

 eral line complete; scales on cheeks in 17 rows; 10 to 12 rows of scales 

 between dorsal fin and lateral line. 



Color green to nearly black, with faint vermiculations above lat- 

 eral line and indistinct dark bars below it. 



Length 12 to 15 inches. . / 



This fish inhabits the clear streams and colder lakes from the 

 Great Lake Region to Vermont, South Carolina, and Arkansas. 



Fox River, McHenry, Illinois; Des Plaines River, Berwyn, Illinois; 

 Hickory Creek, New Lenox, Illinois. 



Micropterus salmoides (Lacepede). Large-mouthed Black Bass. 



Head 2.8 to 2.9; depth 2.9 to 3.2; D. x, 12 to 13; A. in, 10 to 

 12; scales 62 to 68. 



Body elongate, not much compressed ; dorsal region little elevated ; 

 mouth large, the maxillary reaching past posterior margin of orbit, 

 its length 1.9 to 2.1 in head; supplemental bone well developed; eye 

 5.8 to 7.6 in head; snout 3.1 to 3.9; gill rakers long; spinous dorsal 

 low, its last rays much shorter than longest ones; pectorals short 

 2,0 to 2.4 in head; lateral line complete; scales on cheeks in 9 or 10 

 rows; 8 to 9 rows of scales between dorsal fin and lateral line. 



Color dark-green, obscurely mottled with dark blotches; a dark 

 lateral band, most conspicuous in smaller individuals. 



Fiu. 64. Larqemoutheo Black Bass. 



Microt>t«rtiK Halmoiili-n (I^i-.), (Afii-r I'(>rt>o» ami Kuhardson.) 



