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. iii, 10 to 

 12 ; scales 66 to 78. 



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

 illary not reaching posterior margin of orbit; its length 2.1 to 2.5; 

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

 to 3.;^', gill rakers long, spinous, dorsal lo\v, 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. 



y-//. 



Fig. 64. Large-mouthed Black Bass. 



Micropterus salmoides (Lac). (After Forbes and Richardson.) 



