102 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 
91. P. olavaris (Raf.) Gill & Jordau. — Mud Cat; Yellow Co, f ; Bashaw; Goujon. 
Mottled browu and yellowish, the latter color often predominant; 
whitish below. Body very long, slender, depressed forwards, closely 
compressed behind, the head extremely flat, the lower jaw the longer. 
Barbels short. Dorsal spine half the height of the fin. Caudal slightly 
emarginate. Anal fin short, its base about one-sixth the length, its rays 
12-15. Humeral process short. Size very large, reaching a weight of 
50-75 pounds. Eivers of the Mississippi Valley and Southern States ; 
abundant in deep, sluggish waters. A fish of unprepossessing apjiear- 
ance, although much used as food. 
{Silurus olivaris Raf. Amer. Mouth. Mao'. 1818, 356: Ropladelus oUvaris Gill, Ichth. 
Capt. Simpsouts Expl. 1876, 426: Pelodichthijs olivaris Jordan, 1. c. 95: Pinwlodus punc- 
tv.latus Giiuther, v, 101 : Pimelodus limosus Raf. Ichth. Oh. 67 : Pimelodus ceneus C. & V. 
XV, 135.) 
54.— OUONIAS Cope. 
Blind Cats. 
(Cope, Proc. Acad. Nat. Sci. Phila. 1864, 231: type Gronias nif/rilahrls Cope.) 
This genus agrees with Amiurus in all respects, except that the eyes 
are rudimentary and covered by the thick skin. The single species is 
probably descended from some Amiurus of the type of melas, modified 
in accordance with its subterranean life. ^ cavern.) 
92. Cr. nigriSabras Cope. 
Black above ; jaws and fins black ; sides varied with yellowish ; belly 
pale. Eyes more or less rudimentary and concealed beneath the skin. 
Jaws equal. Muzzle flat. Dorsal spine midway between snout and mid- 
dle of adipose fin. Barbels short. Caudal slightly emarginate. Anal 
with 18 rays. Brauchiostegals 10. Cave streams (Conestoga Eiver), 
Eastern Pennsylvania. 
(Cope, Proc. Acad. Nat. Sci. Phila. 1834, 231 : Amiurus nigrilahris Jordan, 1. c. 92.) 
55. — AMIURUS Rafinesque. 
Cat-Jishes. 
(Ameiurvs Rofinesque, Ichth. Oh. 1820, 65: tjpe Silurus eupreus Raf . = Pimelodus natalis 
Le Sueur.) 
Body moderately elongated, robust, anteriorly vertically ovate and 
scarcely compressed ; caudal peduncle also robust, but much compressed, 
and at its end evenly convex. Head large, wide, laterally expanded, 
above ovate, and in profile cuneiform ; supraoccipital extended little 
posteriorly and terminating in a more or less acute point, which is en- 
tirely separate from the second iuterspinal buckler ; the skin covering 
