FISHES 117 



belly with ordinary scales; ventral fins inserted close 

 together. 

 Ci Lateral line complete. 



di Anal fin large, approaching the soft portion of the 



dorsal in size 19. Poecilichthys. 



d2 Anal fin small, much smaller than the soft dorsal. . . 20. Nanostoma. 



21. Nothonotus. 

 Co Lateral line more or less incomplete. 



di Gill membranes not connected 22. Oligocephalus. 



do Gill membranes broadly connected across the 

 isthmus. 



ei Anal spines 2 2^^. Claricola. 



24. Calonolus. 

 26. Hololepis. 



eo But I anal spine present 25. Psychromaster. 



28. Alvarius. 

 d Lateral line wanting 27. Microperca. 



1. Percina Haldeman. Body slender, elongate, slightly com- 

 pressed; midventral line with enlarged plates, which may fall off leaving 

 a naked strip; caudal margin concave; mouth overhung by snout; 

 teeth on vomer and palatines; lateral line continuous; air bladder and 

 pseudobranchiae rudimentary: 2 species. 



P. caprodes (Rafinesque). Log-perch. Length 200 mm.; head 4 to 

 4.7; depth 5 to 6.5 ; color yellowish green, with about 15 black transverse 

 bars extending from the back to the belly and alternating with shorter 

 ones; a round spot at the base of the tail fin; rays of dorsal lin XIII to 

 XV-12 to 17; anal II, 9 to 12; scales 9-90 to 95-15: Great Lakes region 

 to North Carolina, Mississippi and the Rio Grande ; in Atlantic coastal 

 streams southward to North Carolina; in large, clear streams; generally 

 common. 



P. rex Jordan & Evermann. Length 150 mm.; head 4; depth 4.6; 

 scales 11-83 to 85-19; anterior dorsal fin with a broad orange band 

 towards the margin: Roanoke River; rare. 



2. Alvordius Girard. Black-sided darters. Body very small, 

 elongate, cylindrical, brightly colored, but without any red or blue, and 

 with a series of large dark more or less confluent blotches along the 

 lateral line and rounded blotches on the back; mouth terminal; teeth 

 on jaws and vomer and usually the palatines; midventral area with 

 enlarged scales, or with large plates which in most species may be shed, 

 leaving the belly naked; fins large; ventral fins well separated: about 

 9 species. 



A. evermanni (Moenkhaus). Length 100 mm.; head 4; depth 5; 

 color olive, marbled; sides with 13 or 14 blotches; rays of dorsal fins 



