SILURIDiE. — XXIV. 4 1 



and Texas, common, the best known of the smaller Cat-fishes. In- 

 troduced into the rivers of Cal. (Lat., clouded.) 



ff. Pectoral spines short, 2 J to 3 in head (longest in the young) ; A. 17 

 to 19. 



57. A. melas (Rafinesque). Adult very plump; young more 

 slender. Color usually blackish. A. short and deep, its rays 

 usually 17 to 19, its base nearly 5 in length, its pale rays forming a 

 sharp contrast with the dusky membranes. N. Y. to Kansas, gen- 

 erally common ; very close to A. nebulosus. (fj.t\as, black.) 



38. GRONIAS Cope, (ypww;, cavern.) 



58. G. nigrilabris Cope. Upper parts, jaws, and fins black ; 

 eyes nearly hidden by thick skin ; barbels and spines rather short. 

 A. 18. Cave stream, tributary to Conestoga R., E. Penn. A 

 recent descendant of A. melas or 7iebulosu$, rendered blind by 

 subterranean life. (Lat. niger, black ; labrum, lip.) 



39. LEPTOPS Rafinesque. (XenTos, thin ; &\\r, face.) 



59. L. olivaris (Rafinesque). Mud Cat. Flat-head Cat. 

 Russian Cat. Bashaw. Goujox. Yellowish, much mottled 

 with brown. Body slender, the head broad and much depressed, 

 the lower jaw projecting; barbels short; dorsal spine very weak; 

 pectoral spines strong; anal short. A. 12 to 15. C. scarcely 

 emarginate. A very large species, reaching 75 pounds, abundant 

 in sluggish streams, Ohio to Ga. and S. W. A good food fish, of 

 unprepossessing appearance. 



40. NOTTJRUS Rafinesque. Stone Cats. 1 (ixiroy, back ; 



ovpd, tail.) 



a. Premaxillary band of teeth with lateral backward processes, as in Leptops. 

 (Xoturus.) 



60. N. flavus (Rafinesque). Yellowish brown, nearly uniform ; 

 body elongate ; head broad and flat ; barbels short ; adipose fin 

 deeply notched ; a keel on back before it ; D. spines short ; P. 

 spine retrorse-serrate in front, roughish behind; A. 1G. L. 12. 

 Ontario to Ya., Xeb., and Tenn., not rare in large streams. (Lat., 

 yellow.) 



aa. Premaxillary band of teeth without backward processes. (Schilbeodes 

 Bleeker.) 

 6. Pectoral spine serrate on its posterior edge, roughish in front; adipose fin 

 notched. 



1 These little fishes abound in small brooks among logs and weeds. The wounds 

 produced by the sting of their sharp pectoral spines are excessively painful. In the 

 axil is usually a pore, probably the opening of a duct from a poison gland. This 

 matter deserves investigation. 



