FAMILY SILURID.E — PIMELODUS. 187 



P. borealis. (Rich. F. B. A. Vol.3, p. 135.) Pectoral and dorsal spines not serrated. Dorsal sub- 

 quadrangular. Caudal slightly forked, with rounded lobes. A. 25. Length two to three feet. 

 Northern Regions. 



P. lemniscatus. (Lesueur, Mem. Mus. Vol. 5, p. 155.) Caudal united above to the long and low 

 adipose fin, and nearly united to the anal beneath. Length 4-8 inches. Southern Stales. 



P.furcatus. (Id. Cuv. et Val. Vol. 15, p. 136.) Elongate. Tail furcate. Adipose small and nar- 

 row. Anal fin with 32 to 34 rays. Length one to four feet. Ohio, Louisiana. 



P. punctulalus. (Id. Cuv. et Val. lb. p. 134.) Branchial rays twelve. Caudal even. Brown, 

 punctured with black. Anal fin with seventeen rays. Length 2-3 feet. Louisiana. 



P. ceneus. (Id. Mem. Mus. Vol. 5, p. 150.) Lower jaw longest. Eleven anal rays; twenty-five to 

 the even caudal. Allied to the preceding 1 Length 2-3 feet. Ohio. 



Dr. Kirtland, in his Report on the Geology of Ohio, has given a catalogue of six others, some of 

 which are probably included above. 



P. cerulescens. The Blue Catfish of Ohio and the Lakes. 



P. cuprcus. The Yellow Catfish. 



P. pallidus. The Channel Catfish. 



P. nebulosus. The Mud Catfish, recognized by the scarified and clouded appearance of its skin. 



P. xanthocephalus. The small Black Bullhead of the northern streams and lakes. 



P. flavus. Young Catfish, with the rudiments of an adipose fin. 



Genus Amblyopsis.* Body with scales. Vent anterior to the base of the pectorals. Eyes concealed 

 under the skin. Ventrals minute ; a single dorsal. Teeth on the jaws and palatines. Head 

 smooth, and without barbels. 



A. spelams. Whitish. Head broad and flattened. Mouth large. Most of the fins with filamentous tips. 

 Length 3{ inches. Mammoth cave, Kentucky. 



* Note. To add to the usefulness of this work as a hook of reference, I introduce here a species which appears not to 

 have been described, and for which I am in a manner compelled to construct a new genus. It is probably identical with 

 the one noticed in the proceedings of the Academy of Natural Sciences, as follows: " A small white iish, eyeless, (pre- 

 sumed to belong to a subgenus of Silurus,) taken from a small stream called the River Styx, in the Mammoth cave, Ken- 

 tucky, about two and a half miles from the entrance." 



I have been much embarrassed to know where to place this species, and have delayed the publication of these pages, in 

 hopes that some naturalist, with recent and perfect specimens before him, would ere this have favored the public with the 

 result of his observations. The specimen from which I drew up the following notes was imperfect, and as it belonged to 

 a public institution, could not with propriety be dissected. It has obviously the port and habit of the Siluridae, and the 

 obscure character of its eyes naturally recals the genus Cctopsis of Agassiz ; but its scaly body, and head without barbels 

 forbid its arrangement even in that family as at present characterized. In the singular position of its vent, it resembles 

 Aphredoderus among the Percida;. I think it probable that it may form the type of a new family of the soft-rayed abdo- 

 minal fishes. 



A. spelcms. Body cylindrical in front, largest at its junction with the head, tapering and becoming gradually compressed 

 behind. Surface covered with minute soft orbicular scales, becoming smaller on the back and towards the basal line 

 of the head, and beneath the branchial membrane; they do not ascend upon the fins; the course of the lateral is only 

 obvious on the posterior part of the body and tail. Head smooth, broad, flat, and gradually sloping from the elevated 

 nape ; its length to the total length as one to three and a half. Eyes large, vertical, not obvious, but their position 



