126 VERTEBRATE ANIMALS OF THE UNITED STATES 



22. Oligocephalus Girard. Body elongate and brightly colored; 

 lateral line more or less incomplete; ventrals close together at the base; 

 gill membranes not joined across the isthmus; anal spines 2:7 

 species. 



O. exilis (Girard). Length 50 mm.; body slender; head _^.S; depth 

 4 to 5.5; color light green, blotches with darker; sides with 10 or 11 

 large brown spots alternating with black ones; cheeks, opercles and 

 nape scaly; top of head and breast naked; rays of dorsal fins VII 

 to X-io or II ; anal II, 6 to 8; scales 5-55 to 63-11 : Michigan, Iowa and 

 Nebraska, and northward into Canada; common. 



O.jessicE (J. & B.). Length 45 mm.; head 4; depth 4.75; cheeks and 

 opercles scaly; color brownish, with a light lateral band, above and 

 below which are light spots; rays of dorsal fins X to XII- 12 to 14; anal 

 II, 7 to 9; scales 6-47 to 55-8: Michigan to Iowa; southward to Missis- 

 sippi and Texas; common. 



O. luteovinctus (Gilbert & Swain). Body compressed; length 50 

 mm.; head 3.6; depth 4.5 to 5; color light olive, with 7 cross bars; sides 

 with 9 greenish blotches alternating with yellowish bands; cheeks and 

 opercles scaly; rays of dorsal fins IX or X-13; anal II, 7 or 8; scales 6-49 

 to 55-11; tail very slender: Stone River, Tennessee; rare. 



O. cozruleus (Storer) . Rainbow darter. Body stout ; length 60 mm. ; 

 head 3.75; depth 4.25; color olivaceous, blotched with darker; sides 

 with about 12 oblique blue bars with orange between; cheeks blue; 

 breast and throat orange; fins mostly orange and blue; rays of dorsal 

 fins X-12 to 14; anal II, 7 or 8; scales 5-37 to 50-10; neck and breast 

 naked : valleys of the Mississippi and Great Lakes and southwestward 

 to Texas; very common in small streams. 



O. punctnlatus (Agassiz). Body slender; length 50 mm.; head t^.t,; 

 depth 5.75; color dark green, with indistinct darker bars; head punctu- 

 late; belly red; a black spot on shoulder; rays of dorsal fins X or XI- 14; 

 anal II, 8 or 9; scales 9-63 to 80-16; breast, cheeks and opercles naked: 

 Ozark region; not common. 



O. cragini (Gilb.). Length 40 mm. ; head T;,.^) ; depth 4.75 ; color oliva- 

 ceous, mottled; lower half of sides specked with black; sides with a 

 series of small spots; a conspicuous shoulder spot; cheeks and opercles 

 naked; rays of dorsal fins VIII or IX- 10 to 12; anal II, 6 or 7; scales 

 6-46 to 55: western portion of Arkansas River basin, in Colorado; 

 in small brooks; the only darter reaching the base of the Rockies. 



23. Claricola Jordan and Evermann. Similar to Oligocephalus, 

 but with the gill membranes broadly joined across the isthmus (except 

 in C. squamiceps), and with a large black shoulder scale: 4 species. 



