Be. Lower jaw not projecting. 



h. Anal rays more than 20 A. nkbulosob. 



hh. Anal rays 17 to 19. with black membranes A. melas. 



«e. Spines short. ^ the height of fln. a fleshy continuation extendlne about as hieh 

 as fin; spines harmless, muffled by thick skin; head flat; upper portion of 

 caudal fln light or white Lkptops olivabis. 



dd. Adipose fln keel-like and continuous with the caudal fln or separated from 

 It only by a notch. 



I. White crescent under the posterior margin of the dorsal fln evident; head flat- 



tened, with fleshy mounds on either side of a median groove.. Noturus flavus. 



II. White crescent behind dorsal fln absent or obscure; small flshes, not exceedlns: 



6 inches, 

 j. Body heavy; muscle plates evident on sides; longitudinal dark lines at angles 

 of muscle plates Schilbkodes qtrinus. 



jj. Body more slender; color uniform, mottled, punctulate. 



k. Adipose fln continuous with caudal, not separated by notch; color plain black- 

 ish S. N0CTURNU8. 



kk. Adipose fin more or less separated from caudal by notch. 



I. Body not blotched with black; head small; body slender; color in life yellowish, 



brown, or greenish S. exilis. 



II. Body more or less blotched with black; head broad. 



m. Saddle-like blotches faint; adipose and caudal fins entirely separated. 



S. KLEUTHERUS. 



mm. Body mottled with black and gray, with 4 saddle-like blotches on back; adi- 

 pose and caudal not entirely separated S. miurus. 



Ictalurus furcatus (Le Sueur). — Channel Cat; Blue Cat; Great Fork-tailed 

 Cat; Mississippi Cat. 



Taken here and there throughout the State in the larger streams tributary to the Missis- 

 sippi; not, however, so abundant as the common channel cat (7. punctatus) . Recent exami- 

 nations by Dr. Evermann of specimens of the "Mississippi Cat" show it to be this species In- 

 stead of Ameiurus lacustris as previously supposed. (Cf. Bull. U. S. National Museum. 

 Vol. Ill, p. 2789.) 



Ictalurus anguilla Evermann & Kendall. — Channel Cat; Eel Cat; Willow 

 Cat. 



Probably taken in our larger streams with other Ichannel cats, but not yet positively 

 recognized. 



Ictalurus punetatus (Rafinesque). — Channel Cat; Blue Cat; White Cat. 



The most abundant of the channel cats. An excellent and marketable food fish. The 

 youngstay most frequently in the deep swift water of the rivers and larger creeks. A 

 strong swimmer. 



Our collections of this species are from 123 localities, distributed throughout the State 

 with the exception of the upper Illinois valley above the mouth of the Fox River, and the 

 Lake Michigan region. It occurs, however, in three collections from Iroquois county. It 

 does not appear to be common southward of the Illinois basin. 



Ameiurus lacustris (Walbaum). — Catfish of the Lakes. 



Known from other Illinois members of this genus by its forked tail, larger number ol 

 anal rays, and silvery appearance. In these respects it approaches the genus Ictalurus, hnt 

 difl'ers in not having the occipital process articulated with the bones at the base of the dor- 

 sal fln. 



Doubtless not so common in Illinois as hitherto supposed; until lately generally confused 

 with Ictalurus furcatus, under which see note. 



Ameiurus natalis (Le Sueur). — Yellow. Cat; Yellow Bullhead. 



Body thick; skin very smooth and thin. Called by fishermen "greaser" or "greased cat." 

 and readily separated by them from other bullheads. 



Common throughout the State, except in streams tributary to Lake Michigan, and in the 

 northwestern portion of the Illinois and Fox basins, occurring in the latter region only In 

 collections from Carthage, Hancock county. Taken, in all, from 76 localities. 



Ameiurus vulgaris (Thompson). 



Apparently rare in Illinois; possibly not distinguishable from A. melas 



