FAMILY SILURID.C — PIMELODUS. 187 



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

 quadrangiilar. Caudal slightly forked, with rounded lobes. A. '2u. Length two to three feet. 

 Northern Regions. 



P. kmnlscatiis. (Lesueur, Mem. Mus. Vol. 5, j). 155.) Caudal united abovt; to the long and low 

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



P.furcalus. (Id. Cuv. et Val. Vol. 15, p. 13(3.) Elongate. Tail furcate. Adipose small and nar- 

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



P. ptuictulatus. (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. aneus. (Id. Mem. Mus. Vol.5, p. 150.) Lower jaw longest. Eleven anal raj-s; twenty-five to 

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



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

 whicli are probably included above. 



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



P. cupreus. The Yellow Catfish. 



P. pallidus. The Channel Catfish. 



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



P. xantlwccphalus. The small Black Bullhead of the nortlicrn streams and lakes. 



P.flai-us. Young Catfish, with the rudiments of an adipose fm. 



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. spelaus. Whitish. Head broad and flattened. Mouth large. Most of the fms with filamentous tips. 

 Length 3J- inches. Mammoth cave, Kcntuck)/. 



* Note. To adJ to the usefulness of this work as a book 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 fish, eyeless, (pre- 

 sumed to bcloncr 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 Iiefore him, would ere this have favored the public with the 

 result of liis 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 Siluridie, and the 

 obscure character of its eyes naturally recals the genus Cclnpsis 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 

 Ap/iralmhnis among the Percidas. I think it probalile thai it may form the type of a new family of the soli-rayed abdo- 

 minal fishes. 



A. speltms. 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, broarl, flat, and gradually sloi)lng from the elevated 

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



