106 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 



Greatest width of the head contaiued about IJ times in its length. 

 Dorsal fin slightly nearer the snout than the adipose fin, unusually 

 high, its spine long, as in the species of Ictalurus. Pectoral spine very 

 strong, about half as long as the head. Anal tin long, deep, nearly one- 

 third the length of the body, and composed of 24 rays. Adipose fin 

 large. Caudal fin rather short, truncate behind. Jaws equal. iSupra- 

 occii)ital bone but little free behind. Branchial apertures rather more 

 restricted than usual. Eesembles I. laciistrisy but with the truncK.te 

 caudal of A. natalis. Elvers of Florida. 

 (Jordau, Bull. U. S. Nat. Mus. x, 85.) 



56.— BCTAi.URUiS Rafinesqne. 



Channel Cats. 



(Rafiuesqne, Iclith. Oli. 1820, 61: type SihirHsjyunctatusRh&nesqne.) 



Body elongated, slender, and much compressed. Head usually slen- 

 der and conical. The supraoccipital bone is prolonged backward, and 

 its emargiuated apex, in typical species, receives the acuminate anterior 

 ponit of the second interspinal, thus forming a continuous bony bridge 

 from the head to the dorsal spine. In some species, this connection is 

 more or less imperfect, as in Amiurus, to which genus all such species 

 have been hitherto referred. Mouth transverse and terminal, the up- 

 per jaw protruding beyond the lower. Teeth subulate, aggregated into 

 a short, laterally truncated band on each jaw. Branchiostegal rays 8 or 

 9. Dorsal fin situated over the interval between the pectoral and ven- 

 tral fins, higher than long, with one long spine, and usually G articulated 

 rays. Adipose fin pedunculated, over the posterior portion of the anal. 

 Anal fin long, with 20-35 rays ; it commences near the vent. Ventral 

 fins each with 1 simple and 7 branched rays. Pectoral fins each with a 

 stout spine, retrorse-serrate within, and about 9 branched rays. Caudal 

 fin elongated and deeply forked, with the lobes pointed, the upper fre- 

 quently the longer. Coloration silvery. Fresh waters of North Amer- 

 ica, one species southward to Guatemala;* one in Western Mexico.t 



*I. mc7-idio)ialis (Giiutber) Jordan. Allied to I. furcatus, but the anal shorter, the 

 depth f) in length. A. 28-29. Rio Usumaeiuta, Guatemala. (Amiurus meridionalis 

 Gunther, v, 102.) 



t/. dugcsi (Bean) J. & G. Closely allied to /. albidus, but with a narrower head (its 

 width 5 in length) ; the width of the premaxillary band of teeth about one-third the 

 length of the head ; humeral process slightly furrowed, not strongly rugose as in J. 

 albidus. Caudal deeply forked. Color plumbeous, silvery below. B. 8 ; D. I, (> ; A. 

 21 ; P. I, 8. Rio Turbio, Guanajuato, Mexico (west of the Sierra Madre). {Amiurus 

 dugesi Beau, Proc. U. S. Nat. Mus. ii, '304, 1879.) 



