48 thk fishes of ohio. 



Genus: Opsopoeodus. 

 Key to Species. 



A. Lateral line complete or very nearly so; dorsal fin with black blotch on anterior 

 rays, usually none on the posterior. — entities. 



AA. Lateral line always incomplete; dorsal usually with a conspicuous black spot on 

 posterior rays. — megalops. 



Opsopoeodus emiliee Hay. 



Head about 4^; depth 4§; eye 3. D. 9; A. 8; scales 5-40-3; teeth 5-5,. 

 very slender, strongly hooked, and deeply serrate. Body rather elongate, 

 moderately compressed, not elevated. Head short and slender. Muzzle 

 blunt and rounded. Mouth very small and very oblique, smaller than in 

 any other of our Cyprinidce, with scarcely any lateral cleft. Caudal peduncle 

 long and slender, caudal deeply forked, Breast naked; 16 scales before 

 dorsal. Lateral line complete or very nearly so. Yellowish; sides silvery; 

 scales above dark edged; usually a dark lateral band from snout to caudal, 

 above and below which are series of black dots; anterior rays of dorsal dark,, 

 no black spot on the posterior raj^s. 



Given by Jordan and Kvermann (Bull. 47) for L,ake Erie ; 

 " two small specimens from the St. Mary's river at St. Mary's," 

 Kirsch, 1893. 



Opsopoeodus megalops (Forbes). 



Head 4^; depth 4 to 5; eye 2j^. D. 7 or 8; A. 7 or 8; scales 5-39-4, 15 

 before dorsal. Teeth 5-5, hooked and crenate. Lateral line always incom- 

 plete, sometimes on 4 or 5 scales only; sometimes extending with interrup- 

 tions to middle of caudal peduncle. Body slender, fusiform; mouth small, 

 terminal, oblique, so much so in old specimens as to appear almost vertical, 

 »the chin projecting beyond mouth, in younger specimens the mouth is less 

 oblique. Top of head covered with prickles in old males. Fins large, caudal 

 deeply forked. Breast partly naked. Yellowish brown, sides silvery; scales 

 above dark-edged. Dorsal fin with a black blotch on 4 anterior rays; a 

 second black blotch usually present on 3 posterior rays. Length 2^ inches. 



I have given above the separation of O. emiliee and O. mega- 

 lops as given by Jordan and Evermann (Bull. 47, U. S. Natl. 

 Mus. ) They suggest in regard to O. megalops that it is " per- 

 haps not a distinct species. ' ' A comparative study of these forms 

 confirms this belief. A dozen specimens taken by the writer in 

 the headwaters of the Wabash river at Celina, August, 1899, and 

 two from Summit lake at Akron, July 30, 1900, are referable to 

 O. megalops as given above, but so many variations between 



