18 FISHES OF PENNSYLVANIA. 
This catfish was first discoved by the late Jacob Stauffer, near Lancas- 
ter, Pa,, and has since been obtained by a number of persons. It has 
the general appearance of the black catfish previously described, Amiu- 
rus melas, but the eyes are rudimentary and concealed under thick skin. 
It is believed to be a recent descendant of the common black catfish or 
perhaps thecommon catfish, A. nebulosus, and that its condition of blind- 
ness is due to its cave life. It is the only blind catfish known. The 
cave catfish grows to a length of ten inches. 
Genus LEPTOPS Rarrnesave. 
20. Leptops olivaris Rarresqvz. 
The Mud Catfish. 
The yellow cat or mud cat has a long slender body, with the head much de- 
pressed. The dorsal profile is gradually elevated from tip of snout to origin of dor- 
sal fin ; from this point to tail the slope is very slight. The depth of the body at be- 
ginning of dorsal is about one-sixth of the total length, without caudal. The length 
of the head is contained two and two-thirds times in the standard length. The head 
is very flat. Eyeverysmall. Maxiulary barbelalmost as long as head. Dorsalrays 
about equal in length ; height of dorsal equal to length of anal base: the spine one- 
half as long asrays. Fins rounded ; caudal emarginate; adipose fin large, its length 
equal toanal base. Anal and adipose fins opposite. D. I,6; A. 13; V.1,8 De- 
scribed from No. 27,873, United States National Museum, collected in the Illinois 
river by Prof. 8S. A. Forbes. 
This is known under the name of mud-cat, flat-head cat, Russian cat, 
yellow cat and goujon. 
The mud-cat in Pennsylvania is limited to the Ohio and its tributaries. 
It is abundantin the Mississippi valley in deep siuggish waters, ranging 
westward to Iowa and southward to Georgia, but is not found in tribu- 
taries of the Atlantic. 
This is a very large species reaching a weight of seventy-five pounds, 
and amaximum length of three feet. Themud-cat prefers muddy bottoms 
and large sluggish streams. It is a food fish of good qualities and is 
extensively used notwithstanding its ugliness. 
Genus NOTURUS Rarrnesave. 
21. Noturus flavus RarinesQue. 
The Stone Catfish. F 
The stone cat has a moderately elongate body, whose greatest depth and width are 
nearly equal; the tail is much compressed, and the head flat and broad. The great- 
est depth of the body is nearly one-fifth of the total length without the caudal; the 
least depth of the caudal peduncle equals nearly one-half length of head. The 
mouth is terminal, horizontal, its width equal to postorbital yart of head and to 
length of maxillary barbel. Longer barbel on chin not quite one-half as long as the 
head. Nasal barbel, when laid back, reaches end of eye. The width of the band of 
teeth in the upper jaw equals one-third length of head; the backward prolongation 
is little longer than the eye. The distance between the eyes equals length of snout 
and eye. The snout is one-half as long as the postorbital part of the head. The 
