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



Genus Perca (Artedi). Linnaeus. 



Yellow Perch. 



Body elongate, considerably compressed; head large; mouth 



moderate; premaxillary protractile; preopercle serrate; opercle 



with a single spine; teeth in villifomi bands on jaws; vomer and 



palatines; no canines; pseudobranchias small; pyloric coeca 3 to 7. 



Perca flavescens (Mitchill). Yellow Perch. 



Head 3.0 to 3.5; depth 3.3 to 3.8: D. xii to xiv — 11 or in, 12 or 

 13; A. II, 7 or 8; scales 57 to 62. 



Body moderately elongate, compressed; head large, pointed; 

 interorbital space nearly flat; mouth large, the maxillary reaching 

 middle of orbit; snout pointed 3.4 to 3.7 in head; diameter of eye 

 3.6 to 4.8; preopercle strongly serrate; opercle ending in several 

 points; spinous and soft dorsal separate; cheeks scaled in about 8 

 to 10 rows; gill rakers x + 15; pyloric coeca 3; lateral line complete 

 or nearly so. 



Color brassy green to golden yellow; sides with 7 dark or dusky 

 bars; spinous dorsal gray, usually with a black spot on last 2 mem- 

 branes; soft dorsal and caudal pale-green. 



Length i foot. 



This fish ranges from North Dakota to Nova Scotia, New York, 

 and Iowa. 



Fox River, McHenry, Illinois; Lake Michigan, Chicago, lUinois; 

 Calumet Lake, Pullman, Illinois; Hickory Creek, New Lenox, Illi- 

 nois; Wolf Lake, Roby, Indiana; Lake Michigan and Lagoons, 

 Millers, Indiana; Lagoon, Buffington, Indiana; Lake Michigan and 

 Lagoons, Pine, Indiana; Calumet River, Clark, Indiana; Lake Mich- 

 igan and Lagoons, Edgemoor, Indiana. 



Genus l*«'rriiia Haldeman. 



Body elongate, scarcely compressed; premaxillary not protrac- 

 tile; teeth on vomer and palatines ; mouth small and inferior; pyloric 

 coeca 6; ventral surface with a row of enlarged scale-like caducous 

 plates. 



Percina caprodes (Rafinesquc). Loo-perch. 



Head 3.6 to 4.8; depth 5.4 to 7.0; D. xii-15; A. 11, loor 11; scales 

 83 to 93. 



