29. SILURID^ — ICTALURUS. 107 



(r/Oi)^, fish; adouju,:;^ Cat; heiicemore correctly, tliougli less euphonious- 

 ly, Ichthcvlunis.) 



a. Bony bridge from occiput to dorsal not quite coutinuous. 

 b. Anal tin moderate, of 20-22 rays. 



lOiJ. I. lopllilBS (Cope) J, &G. 



Palo olive-bluish, silvery below. Body rather stout. Head very 

 broad, about as wide as long, its width 3^ in length of the body. Eye 5-6 

 in iuterorbital width. Caudal not deeply forked. Upper jaw not much 

 the longer. Mouth wider than in any other cat-fish. Humeral pro- 

 cess stout, shortish, somewhat rugose. Anal rays 21 ; base of anal 6 in 

 length. L. 24 inches. Streams about Chesapeake Bay. 



{Amiurm lopliius Cope, Proc. Amer. Phil. Soc. 1^:^70, 483 : Aviiurus lopMus Jordan, 

 1. c. 85.) 



103. I. albidus (Le Sueur) J. & G.— White Cat; Channel Cat of the Fotomac. 



Pale olive-bluish, silvery below. Body moderately stout. Head longer 

 than wide, its width 4-6 times in length. Mouth rather narrow. Upper 

 jaw much the longer. Eye 3-5 in iuterorbital width. Barbels long, 

 except nasal barbel. Caudal fin deeply forked, the upper lobe the longer. 

 Humeral process more than half the length of the spine, extremely 

 rugose. Anal rays 21 ; base of anal 4^-5 in length. Dorsal fin nearly 

 midway betAveen adipose fin and snout. L. 18 inches. Pennsylvania 

 to North Carolina. 



(Pimclodus albidus Le Sueur, Mdm. Mu&. v, 148, 1819 : Pimelodus lynx Girard, Proc. 

 Acad. Nat. Sci. PMla. 1859, 160 : Amiurus albidus Jordan, 1. c. 84.) 



bb. Anal fin long, of 23-27 rays. 



104. I. lupus (Grd.) J. & G. 



Dusky olivaceous, sides silvery. Body rather slender. Head narrow, 

 longer than broad, its width 4| in length, being less than its length 

 above. Dorsal spine much nearer snout than adipose fin. Base of anal 

 as long as head. Anal 23. Pectoral spines long and slender, dentate. 

 Barbels long. Supraoccipital bone almost meeting the interspinal ; its 

 relations therefore very close to Ictalurus punctatus. Streams of Texas. 



(Pimclodi/.8 lujms Gvd. U. S. Pac. E. R. Expl. x, 211: Amiurus hqjus Jordan, 1. c. 83: 

 Amiurus lupus Giiutlier, v, 101.) 



10.5. I. niveiveuitris (Cope) J. & G. 



Similar to I. lupits, but the head broader, its widtli equal to its length 



above. Dorsal spine scarcely nearer snout than adipose fin. Anal 



24, shorter than head. Barbel longer than head ; humeral process very 



rugose. Neuse Eiver, North Carolina. 



(Amiurus nivdventria Cope, Proc. Amer. Phil. Soc. 1870, 486: Amiurus niveiventria Jor- 

 dan, 1. c. 83.) 



