SUCKERS. 803 



gg. Second anal spine many times as large as the first. Scr^NiD^. 25. 

 oc. Doral fin continnons, with lees than five spines. 



h. Vent anterior, near or in front of ventrals ; bones of head serrated. 



APHODODBKIDiE. 20. 



hh. Vent normal; bones of head entire ELASSOMATiDiE. 21. 



6i. Anterior dorsal of soft rays only ; a barbel at tip of lower j a,w. 



GADIDiE. 27. 



aa. Skin naked or prickly ; head broad ; dorsal fins two. . Cottidje. 26. 



FAMILY VIII. CATOSTOMID.^. THE SUCKERS. 



Body oblong or elongated, covered with cycloid scales of moderate or large size ; 

 head moderate, naked, the opercular bones normally developed ; nostrils double ; mouth 

 commonly more or less inferior, nsually with thickened lips ; the upper jaw is formed 

 in the middle by the small, lamelliform premaxillaries and on the side by the max- 

 illaries ; no barbels ; no teeth in the jaws ; pharyngeal bones falciform, with a single 

 row of many compressed teeth which grow smaller upward ; branchial openings 

 restricted to the sides, separated by a broad isthmus; branchiostegals three; dorsal 

 variously developed, the number of rays from nine to fifty ; anal short and high ; caudal 

 emarginated or forked; pectorals placed low: ventrals abdominal; intestinal canal 

 very long ; stomach simple, without pyloric ccoca ; air bladder large, not protected by a 

 bony capsule, divided by transverse contrictions into two or three regions. Pishes of the 

 fresh water, all but two of the known species being American. The latest authority on 

 the group (Jordan, Bull. U. S. Nat. Mus., xii, 1878 ) recognizes 55 species, arranged 1q 13 

 genera. These fishes feed chiefly on vegetable substances, and on worms, ova, insect 

 larvse, crustaceans, and small mollubks. All are used as food, but none of them are 

 much valued as the ilesh is coarse, soft, tasteless, and full of small bones. The young of 

 some of the species abound in every brook and pond in the State of Ohio, and they 

 form one of ihe most characteristic features of our fish fauna. 



Analysis of Genera of CATOSTOMiD^a;. 



"Dorsal fin elongated, more or less elevated in front, of 25 or more rays; air bladder 

 in two parts. 

 t Fontanelle present ; body oblong ovate ; scales large ; head large. 



a. Mouth large, terminal, protractile forwards ; lips thin, nearly smooth. 



ICUTHTOBUS. 14. 



aa. Mouth small, subinferior, protractile downward. 

 Z>. Pharyngeal bones strong, the teeth coarse and large, increasing in size down- 

 ward Btjbalichthys. 15. 



hh. Pharyngeal bones, narrow, their teeth thin and weak. . Cakpiodes. 16. 

 tt Fontanelle obliterated by the union of the parietal bones ; body elongate ; 

 scales small ; head small. . . .... Ctclepius. 17. 



**Dor8al fin short, subquadrate, with ten to eighteen rays ; body oblong or elongate, 

 c. Air bladder in two parts. 

 d. Lateral line complete ; lips papillose ; scales moderate or small. 



Catostomus. 18. 

 dd. Lateral line interrupted or wanting ; lips plicate ; scales large. 



