296 Field Museum of Natural History — Zoology, Vol. VII. 



aaa. Lower half of cheeks and opercles without scales; branch- 

 iostegals 17 to 19; dorsal rays 17 ; about 150 scales in the lateral 

 series. masquinongy, 297 



Esox vermiculatus Le Sueur. Little Pickerel; Grass Pike. 



Head 3.0 to 3.4; depth 5.2 to 6.7; D. 12; A. 12; scales 103 to 108. 



Body elongate, moderately compressed; head depressed; inter- 

 orbital concave; mouth large, the maxillary reaching past anterior 

 margin of eye, its length 2.0 to 2.4 in head; snout 2.4 to 2.7 ; eye situ- 

 ated in middle of the head, its diameter 5.5 to 6.8; branchiostegals 11 

 or 12; cheeks and opercles with scales; depth of caudal peduncle 2.0 

 to 2.6 in head; caudal fin forked. 



Color grayish green with darker streaks and reticulations on sides, 

 lighter below; a dusky streak from eye across cheek and opercle, and 

 one below eye; caudal fin mottled near base; other fins plain, dusky. 



Length 12 inches. 



This fish inhabits ponds, lakes, and sluggish streams, whose veg- 

 etation is plentiful, from Wisconsin to Ohio, Mississippi, and Arkansas. 



Fox River, McHenry, Illinois; Dead River, Beach, Illinois; Bull 

 Creek, Beach, Illinois; Ravine, Glencoe, Illinois; Lagoon, Jackson 

 Park, Chicago, lUinois; Des Plaines River, Berwyn, Illinois; Salt 

 Creek, Lyons, lUinois; Hickory Creek, New Lenox, Illinois; Wolf 

 Lake, Roby, Indiana; Lake George, Indiana; Lagoon, Buffington, 

 Indiana; Lagoon, Pine, Indiana; Calumet River, Clark, Indiana. 



Esox lucius Linnaeus. Common Pike; Pickerel. 



Head 2.9 to 3.6; depth 5.0 to 7.0; D. 15 or 16; A. 14 or 15; scales 

 122 to 125. 



Body elongate, compressed; mouth very large, the maxillary 

 reaching past orbit, its length 2.0 to 2.2 in head; snout 1.9 to 2.4; 

 eye in middle of head, its diameter 5.8 to 9.5; branchiostegals 14 to 

 16; cheeks with scales; lower half of opercle without scales; depth 

 of caudal peduncle 1.7 to 2.2; caudal fin forked. 



Color of back and sides bluish or greenish gray, yellowish below 

 and white on ventral surface; sides with irregular, light colored 

 spots; dorsal, caudal, and anal fins with roundish black spots; ven- 

 trals with faint traces of spots; pectorals plain. 



Length 3 feet. 



This species inhabits the larger streams and lakes of Northern 

 Europe, Asia, and North America. 



Fox River, McHenry, Illinois; Jackson Park, Chicago, Illinois; 



