30 THE FISHES OF OHIO. 



Order: PEECTOSPONDYU. 



Sub-Order : Evfntognathi. 

 Family: Catostomid^ (The Suckers). 



Key to Genera. 



A. Dorsal fin elongate, developed rays 25 to 50, air bladder in 2 parts. 

 B. Fontanelle present, body ovate, scales large. 



C. Month large, more or less terminal, protractile forward; pharyngeal 



bones and teeth moderate, large species of dark color. — Ictiobus. 

 CC. Mouth smaller, inferior, protractile downward ; pharyngeal bones nar- 

 row, the teeth thin and weak ; smaller species, pale in color. — 



Carpiodes. 

 BB. Fontanelle obliterated by union of parietal bones ; body elongate ; scales 

 rather small ; lips thick and papillose. — Cycleptus. 



AA. Dorsal fin short, 10 to 18 developed rays. 

 D. Air bladder in 2 parts. 



E. Lateral line present, complete and continuous ; scales small, more than 

 50 in lateral line.— Catostomus. 



• EE- Lateral line interrupted or wanting, scales large, less than 50 in lat. line. 

 F. Lateral line entirely wanting. — Erimyzon. 



FF. Lateral line more or less developed, especially in the adult.— 



MlNYTREMA. 



DD. Air bladder in 3 parts ; scales large ; lateral line complete. 



G. Mouth normal, the lower lip entire or merely lobed, the upper lip pro- 

 tractile. 

 H. Pharyngeal bones moderate, the teeth compressed, not molar-like, 



increasing in size gradually downward.— Moxostoma. 



HH. Pharyngeal bones very strong, the lower teeth very much enlarged, 

 cylindrical and truncate, molar-like. — Placopharynx. 



GG. Mouth singular, the upper lip not protractile, greatly enlarged, the lower 

 lip developed as two separate lobes. — Lagochila. 



Ge?ius : Ictiobus. 



Key to Species. 



A. Mouth large, terminal, protractile forward ; lips very thin, lower pharyngeals and 



teeth weak.— cyprinella. 



AA. Mouth smaller, more or less inferior, and with thicker lips ; pharyngeal bones 

 stronger ; the teeth comparatively coarse and large. 

 B. Back scarcely elevated, depth 3 to 2% in length.— urns. 



BB. Back elevated and compressed, depth 2% to 2%.— bubahts. 



Ictiobus cyprinella (Cuvier and Valenciennes). Common Buffalo Fish ; 

 Red-mouthed Buffalo. 



Head very large and thick, $% in length ; depth 2% to $%. Developed 

 rays of dorsal fin 27 to 29 ; anal 9 ; ventrals 10. Scales 7-37 to 41-6. Body 

 robust, moderately compressed, the outline somewhat elliptical, but the back 

 rather more curved than the belly. Opercular apparatus very strong, the 

 operculum forming nearly % the length of the head. Color dull brownish 

 olive, not silvery, fins dusky, length nearly 3 feet. 



