LEPTOPS 193 



Genus LEPTOPS Rafinesque 



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

 and depressed; skull covered with thick skin;; supraoccipital bone en- 

 tirely free from head of second interspinal. Teeth in broad bands on pre- 

 maxillaries 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 oblong, subtruncate, with numerous accessory rays. 

 One species known ; a large catfish, living in the muddy bottoms of deep 

 rivers. 



LEPTOPS OLIVARIS (Rafinesque) 



(mud-cat; yellow cat; goujon; morgan cat) 



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



G., V, 101 (Pimelodus punctulatus) ; J. & G., 102 and 881 (Pilodictisf, 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 . S 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 ex- 

 ceedingly 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 i 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 

 i 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 argest of our river species, is com- 

 mon 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 



