322. Cheeks and opercles scarcely scaled; Penna. southwards 



Alvordius macrocephalus (Cope) Big-headed Darter 

 (Hadropterus macrocephalus (Cope) ) 

 Cheeks and opercles scaled; north-central states 



Alvordms maculatus Girard Black-sided Darter 



Hadropterus macidatus (Girard) 

 (Hadropterus aspro (C. ^ ].) ) 



323. Pectoral fins shorter than the head, scarcely reaching opposite tips of 



pelvics; Penna. to S. Carolina 



Alvordms peltatus (Stauffcr) Shielded Darter 

 (Hadropterus peltatus (Staulfer) ) 

 Pectoral fins about as long as the head, reaching to tips of pelvics or 

 further 324. 



324. Dorsal fins almost contiguous; with much yellow in coloring; with an 



orange band across first dorsal fin; Virginia to N. Carolina 

 Alvordius roano\a (J. & ].) Roanoke Darter 

 (Hadropterus roano\a J. &? J.) 

 Dorsal fins separated by about the diameter of the eye; color plainer; 

 upper fins light and dark barred; Ind. to Arkansas 



Alvordius ouachitae (J. & G.) Ouachita Darter 

 (Hadropterus ouachitae (J. &? G.) ) 



325. Gill membranes not joined; with about ten rays in second dorsal fin; 



no palatine teeth; color yellow, with dark markings; upper fins orange; 

 N. Y. to N. C. and Oklahoma 



Ericosma evides (J. & C.) Gilt Darter 

 Hadropterus evides (J. ^ C.) 

 Gill membranes united across the isthmus; usually with more than ten 

 rays in second dorsal fin; with palatine teeth 326. 



326. Preopercle with fine serrations behind; color yellowish, with dark mark' 



ings; upper fins dark; Ind. to Texas 

 Serraria sciera (Swain) 

 (Hadropterus scierus Swain) 

 Preopercle smooth edged; color dark greenish, with dark markings; S. C. 

 to Louisiana 



Hadropterus nigrofasciatus Agassiz Crawl-a-bottom 



327. Lateral line noticeably incomplete (usually over nine pores missing) 328. 

 Lateral line almost complete (less than seven pores missing) 343. 



328. Premaxillaries protractile (usually with a groove between them and fore' 



head); head flattened and depressed behind the eyes 329. 



Premaxillaries not protractile; no groove between them and forehead; 



head compressed and elevated behind the eyes 330. 



329. With one anal spine; sides dark mottled; with dark bars on dorsal and 



tail fins; Ind. to Texas 



Vadlantia camura (Forbes) Blunt-nose Darter 

 Boleosoma chlorosomum (Hay) 

 With tv/o anal spines; with W-shaped markings along the sides; first 

 dorsal fin with an orange band; Georgia to Tenn. and Arkansas 

 Ulocentra stigmaea (Jordan) Speck 

 (Doration stigmaea (Jordan) ) 



297 



