XOTURUS 195 



inches.* Color above almost uniform olive-green, sometimes blackish; sides 

 of head and body shading to yellowish brown or yellow, belly whitish; a 

 saddle-like or crescentic blotch of yellowish or gray behind dorsal and usually a 

 large but fainter squarish one in front of it; lips, chin, and lower barbels 

 yellow; fins of about same shade as adjacent parts, with edges paler. Head 

 very broad, much flattened above, its length 3.6 to 3.9, its width 4 to 5 in 

 length of body; upper jaw projecting, lips thick and coarsely striate; maxillary 

 barbels short, about half length of head; eye 4.6 to 6 in head, placed high and 

 directed well upward. Dorsal fin small, its distance 2.4 to 2.8 in body, the 

 spine very short, but little more than ^ the height of fin. Caudal not quite 

 symmetrically rounded, the upper posterior margin usually truncate; notch 

 between adipose and caudal deep. Anal fin of about 16 rays. Pectoral spine 

 with a few weak retrorse teeth on its anterior edge near tip, the posterior edge 

 entire or very little roughened; humeral process very short. 



This interesting little fish, commonest under stones in swift 

 waters in the larger creeks and smaller rivers, is rather abundant 

 and widely distributed throughout the northern half of the state, 

 but has not been once taken by us south of Douglas county. 

 It is hence wholly absent from the lower Illinoisan glaciation, 

 and is confined to the Mississippi drainage, in our experience, 

 except for three localities on the headwaters of the Big Vermilion 

 and the Kaskaskia. The frequency ratios of our 40 collections 

 are 3.19 for the smaller rivers, 2.06 for creeks, and .58 for the 

 largest streams. It has not once appeared from stagnant waters 

 of either highland or lowland lakes. Its decided preference for a 

 swift current and a clean bottom is shown by our coefficients 

 of 5.31 for the latter situation and 2.75 for the former. 



The peculiar limitation of the range of this fish in Illinois 

 seems entirely independent of its general distribution, which 

 includes the territory from Canada through the Great Lakes 

 to Virginia and Tennessee, and thence west and southwest to 

 Montana, Wyoming, Nebraska, and Texas. In Indiana it 

 occurs, according to Hay, in the Wabash and its tributaries, 

 in the Kaskaskia, and in Lake Michigan, the St. Joseph River, 

 and the small lakes of northern Indiana. 



The species has very little value as food on account of its 

 small size, which seldom exceeds a length of twelve inches. It 

 is much dreaded by fishermen because of the pain produced by 

 the punctures of its poisoned pectoral spines. It seems to 

 have no common name, being doubtless usually mistaken for 

 a young bullhead. Together with the other stonecats it may 

 be easily distinguished from the bullheads (Ameiurus) by the fact 



* Largest one in our Laboratory collections. Jordan says it sometimes reaches 12 inches. 



