April, 1910. Fishes of Chicago — Meek and Hildebraxd. 333 



Genus Koecus Mitchill. 



Striped Bass. 



Body deep, compressed; mouth large, lower jaw the longer; no 

 supplemental maxillary; lower margin of preopercles serrate or entire; 

 base of tongue with i or 2 patches of teeth; dorsal fins separate; anal 

 spines 3. 



Roccus chrysops (Rafinesque.) Striped Bass. 



Head 3.1 to 3.4; depth 2.6 to 2.9; D. ix-i, 13 or 14; A. in, 11 to 

 13; scales 52 to 57. 



Body rather deep, compressed; the back elevated; head sub- 

 conical; interorbital convex, 3.4 to 4.1 in head; mouth terminal ob- 

 lique, maxillary reaching middle of orbit; lower jaw the longer; gill 

 rakers as long as the gill filaments; cheeks and opercles with 10 to 12 

 rows of scales; lateral line usually complete. 



Color silvery, tinged with golden below" ; sides with narrow dusky 

 lines, about 5 above lateral line, one coincident with it, and a variable 

 number below it. 



Length 12 to 18 inches. 



This species inhabits the Great Lake Region and the Mississippi 

 Valley north of Arkansas. 



Genus Morone Mitchill. 



Body rather short, deep, compressed; no supplemental maxillary; 

 lower margin of preopercle serrate or entire; base of tongue without 

 teeth; spinous and soft dorsals connected by a membrane; anal 

 spines 3 ; scales ctenoid. 



Morone interrupta Gill. Yellow Bass; Striped Bass. 



Head 3.0 to 3.2; depth 2.7 to 2.9; D. ix-i, 12; A. in, 10; scales 

 51 to 55. 



Body deep and compressed, the back elevated; head subcorical, 

 pointed, jaws about equal; interorbital space slightly convex, 4.0 to 

 4.7 in head; snout 3.1 to 3.7; mouth terminal, the maxillary barely 

 reaching to middle of the orbit; gill rakers longer than the filaments; 

 snout 3.1 to 3.7; dorsal fins connected; cheeks and opercles with 

 about 12 rows of scales; lateral line complete or nearly so. 



Color olive-buff to silvery; 3 dark lateral stripes above lateral line, 



