FAMILY SILURIDA — PIMELODUS. 185 
THE BLACK CATFISH. 
PIMELODUS ATRARIUS. 
PLATE XXXVI. FIG. 116.—(CABINET OF THE LYCEUM.) 
Characteristics. Black. Adipose dorsal long and slender ; the rays of the fins passing beyond 
the membrane. Caudal emarginate, round, with numerous accessory rays. 
Length four to eight inches. 
Description. Surface smooth and scaleless. Lateral line distinct, nearly straight, slightly 
convex under the dorsal fin. Head depressed, sloping. The barbels, in number and arrange- 
ment, resemble those of the preceding species. Lips fleshy, with minute punctures. Teeth 
in the jaws minute, long, conical and crowded. ‘Tongue smooth. Humeral bone with a long 
concealed spine above the pectoral, and a short blunt rudimentary process directed downward 
at the upper angle of the branchial aperture. 
The dorsal fin higher than long, arising midway between the pectorals and ventrals; the 
first ray an acute triangular spine ; its anterior surfaces marked with oblique rug or wrinkles ; 
its anterior edge smooth; a small accessory bone at its anterior base; six soft rays, the first 
and second longest.. The adipose dorsal as far from the last rays of the first dorsal, as the 
anterior ray of that fin is from the end of the snout; long and slender, rounded, and laci- 
niate at the tips. The pectoral fins nearly on the plane of the abdomen, and anterior to the 
upper angle of the branchial aperture, containing one spinous and seven branched rays: the 
spinous ray robust, triangular, slightly curved, with its anterior edge roughened, and its sides 
channelled as in the spine of the first dorsal; a small filamentous ray is connected with it, its 
posterior edges with decurved spines; the second, third and fourth rays somewhat longer 
than the spines. Ventrals small and feeble, pointed, their tips scarcely reaching the third 
anal ray; the third and fourth rays longest. Anal fin long; the first four successively longer, 
when they become subequal to the last four or five rays, when they gradually diminish in 
length. Caudal slightly emarginate, rounded at the tips. 
Color. Deep black, occasionally blackish brown above and on the sides ; ashen grey beneath. 
Length, 4°5. 
Binrays), Dy l6.05 Poles VeiS Ar 20a C2178: 
This species occurs commonly in Wappinger’s creek, a tributary of the Hudson, Dutchess 
county. They occasionally occur there of dimensions larger than those given above. 
In concluding the history of the Siluride observed in the State of New-York, I must call 
the attention of our ichthyologists to a species which has been rather indicated than described 
by Dr. Mitchill in the American Monthly Magazine for 1818. If there be no error in the 
description, it will form the type of a new genus in this family, already so rich in the variety 
of its forms. It approaches the Silurus of Cuvier and Valenciennes, of which they observe, 
Fauna — Part 4. 24 
