LEPTOPS 193 



GENUS LEPTOPS EAFINESQUE 



Body elongate, and much depressed anteriorly. Head large, wide and 

 depressed; skull covered with thick skin; supraoccipital bone entirely free 

 from head of second interspinal. Teeth in broad bands on premaxillaries 

 and dentaries, the band of teeth on upper jaw continued backward on each 

 side in an elongated triangular extension. Lower jaw longer than upper. 

 Dorsal spine enveloped in thick skin. Anal rays about 13. Caudal ob- 

 long, subtruncate, with numerous accessory rays. One species known; a 

 large catfish, living in the muddy bottoms of deep rivers. 



LEPTOPS OLIVARIS (EAFINESQUE) 

 MUD-CAT; YELLOW CAT; GOUJON; MORGAN CAT 



(MAP LVI) 



Raflnesque, 1818, Amer. Month. Mag., 355 (Silurus). 



G., V, 101 (Pimelodus punctulatus) ; J. & G., 102 and 881 (Pilodictis) ; M. V., 41; J. 



& E., I, 143; N., 50 (Hopladelus) ; J., 67 (Pelodicthys) ; F., 83; F. F., II. 7, 462; 



L,., 10. 



Body elongate, depth 4.4 to 5.2 in length, back broad and flattened as 

 far back as origin of ventrals, the region between ventrals and front of adipose 

 very nearly cylindrical; caudal peduncle narrow and compressed, 2.5 to 3.1 

 in head; profile straight as far as nape, the elevation from nape to dorsal 

 somewhat abrupt. Size large, reaching a weight of 50 to 75 pounds. Color 

 usually dark olive, variously mottled in the young, the mottling tending to 

 become obsolete in adults; upper parts darker, belly yellowish or grayish; 

 fins colored about as adjacent parts of body, usually darker near margins; 

 dorsal and adipose fins marbled with darker in young specimens. Head long 

 and very broad, much depressed and exceedingly flattened above, its length 

 3.2 to 4, its width 3.7 to 4.4 in length of body; interorbital space very wide 

 and almost flat, 2 to 2.4 in head; lower jaw longer than upper, lips rather thin: 

 barbels short and slender, the maxillary pair falling much short of gill-opening; 

 eye very small, 8 to 14 in head, situated far forward and high up on head and 

 directed obliquely upward. Dorsal spine very slender, its length about Y^ 

 height of fin; distance from snout 2.3 to 2.5 in length. Caudal very little 

 emarginate. Anal short, its rays 12 to 15. Pectoral spine short and robust, 

 3 to 4.4 in head, much flattened dorso-ventrally, its anterior and posterior 

 edges roughened or weakly serrate; humeral process short, its length less 

 than % of pectoral spine. 



This huge catfish, one of the largest of our river species, is 

 common in the Illinois and the Mississippi rivers, and occurs in 

 our collections from the Rock and the Wabash. We have it 

 also from a branch of the Little Wabash, in Wayne county; 

 from Crooked creek, in Brown county; and from Spoon and 

 Green rivers. Our frequency coefficients are 3.25 for the larger 

 rivers, 1.29 for the smaller, .5 for lowland lakes, and .34 for 

 creeks. It is perhaps best known to the fishermen of the Missis- 

 sippi River as the " Morgan cat," and less often referred to as 



