APRIL, 1910. FISHES OF CHICAGO MEEK AND HILDEBRAND. 291 



Coregpnus quadrilateralis Richardson. MENOMINEE WHITEFISH. 



Heads; depth 4. 7; D. n; A. 10; scales 80 to 90. 



Body elongate, not much compressed, the dorsal region little 

 elevated; head long, the snout compressed and bluntly pointed; in- 

 terorbital space 3.5 in head; diameter of eye 4.7 to 5.5; snout 3.8; 

 mouth narrow, small, the maxillary not reaching eye; gill rakers 

 short and stoutish, 7+10 in number, lower jaw the shorter; lateral 

 line complete. 



Color dark bluish above, silvery below. 



Length 1 5 inches. 



Lakes of New England, Great Lakes to the Yukon. 



Lake Michigan, Chicago. 



Genus Argyrosomus Agassiz. 



CISCOES; LAKE HERRINGS. 



Body elongate, little compressed; head larger, the snout pointed, 

 the premaxillary with its cutting edge nearly horizontal; lower jaw 

 the longer; jaws toothless or nearly so; gill rakers long and slender; 

 about 40 on the lower limb; caudal fin deeply forked. 



a. Lower fins pale, or slightly tipped with darker. 



b. Eye large, its diameter not much if any less than^the length 

 of the snout, 3.5 to 4.5 in head. 



c. Maxillary 3.3 to 3.6 in head; lower jaw projecting beyond the 

 upper; gill rakers long and numerous, about 47 on first arch. 



huronius, 291 



cc. Maxillary 2.6 to 3.0 in head, lower jaw scarcely projecting; gill 



rakers 39 to 40 on first gill arch. hoyi, 292 



bb. Eye small, its diameter less than length of snout, about 5 in 



head; mandible half as long as head. prognathus, 292 



aa. Lower fins blue black; gill rakers at least 50 on the first arch. 



nigripinnis, 293 

 Argyrosomus huronius Jordan & Evermann. LAKE HERRING; 



Cisco AND BLUEBACK HERRING OF LAKE MICHIGAN. 

 Head 4.1 to 4.5; depth 4.5 to 5.2; D. 10; A. 12; scales 75 to 90. 

 Body elongate, not much compressed; head rather long pointed; 

 mouth large, the maxillary reaching nearly to middle of the pupil; 3.2 

 to 3.5 in head; lower jaw the longer; mandible 2.1 in head; inter- 

 orbital space 3.3 in head; diameter of eye 4.0 to 4.5 ; snout 3.5 to 4.0; 

 gill rakers long and slender, 15 to 17+28 to 34 on first arch; lateral 

 line complete. 



