322 FIELD MUSEUM OF NATURAL HISTORY ZOOLOGY, VOL. VII. 



Body elongate, slightly compressed; head pointed; interorbital 

 space flat, narrow; mouth large, terminal, the maxillary reaching 

 past front of orbit; cleft of mouth 3.0 to 3.4 in head; snout bluntly 

 pointed, 3.6 to 4.1 in head; eye 3.4 to 4.0; spinous and soft dorsals 

 usually separate; separation of ventrals about equal to their width 

 at base; gill membranes united to the isthmus; cheeks and opercles 



FIG. 67. BLACK-SIDED DARTER. 



Hadropterus aspro (Cope and Jordan). (From Forbes and Richardson.) 



covered with small scales; nape naked or with embedded scales; 

 breast naked; middle line of ventral surface with enlarged caducous 

 plates. 



Color olivaceous; back with about 8 dark quadrate spots; 7 or 

 8 large dark blotches along side more or less confluent into a lateral 

 band; head dark-olive with a dark streak before eye and one below; 

 it ; spinous dorsal in males crossed by a dark band ; pectorals faintly" 

 barred. 



Length 3 to 4 inches. 



This species ranges from Manitoba and the Great Lake Region to 

 Arkansas. 



Fox River, McHenry, Illinois; Des Plaines River, Berwyn, Illinois; 

 Flossmore, Illinois; Thorn Creek, Thornton, Illinois; Salt Creek, 

 Lyons, Illinois. 



Genus Cottogaster Putnam. 



Body rather robust, little compressed; premaxillary protractile, 

 or with a narrow frenum; teeth on vomer; mouth small, subter- 

 minal; pyloric cceca 3, ventral surface naked or with caducous plates. 



Cottogaster shumardi (Girard). SHUMARD'S DARTER. 



Head 3.7 to 4.0; depth 5.2 to 6.9; D. ix to xi 13 to 15; A. n, 

 10 to 12; scales 50 to 56. 



Body elongate, little compressed; head large, snout blunt; mouth 



