ETHEOSTOMA 311 



first-class rivers, and but twice from lakes or sloughs, while the 

 coefficients of frequency for creeks and the smaller rivers are 

 2.72 and 2.66 respectively. It is also differently distributed 

 throughout the state, being more abundant northward in our 

 collections than jessice, much less so in the central part of the 

 state, and somewhat more abundant, again, in extreme southern 

 Illinois.* While it occurred three times in the waters of the 

 lower Wabash within the lower Illinoisan glaciation, a compari- 

 son of the map of its distribution with that of jessice indicates 

 unmistakably an avoidance of this area by the present species. 

 It is distinctly a swift-water and clean-bottom species — 83 per 

 cent, of our collections bearing ecological data having come from 

 the former and 92 per cent, from the latter situations. 



In general distribution it ranges from Lake Superior to Lake 

 Ontario, New Jersey, and western Pennsylvania, and thence 

 throughout the Ohio and the Missouri basins to Missouri and 

 Kansas, and southwest to Texas. 



It is a thick-bodied fish, without much grace of appearance 

 or movement, but is very active and alert and always watchful 

 of its surroundings. When alarmed it darts swiftly to the right 

 and left, with confusing rapidity. It is fond of creeping into 

 crevices in the aquarium, and is quite skilful at hiding itself in 

 the sand or gravel by a headlong dive and one or two vigorous 

 flirts of the tail. 



We have taken females filled with large eggs and males in 

 breeding color in early June. Their spawning habits are de- 

 scribed by Mr. W. P. Seal, who observed them in the aquarium. 

 The eggs were deposited among the pebbles at the bottom of 

 the tank, the female drawing herself along with a quivering 

 motion, and the male pushing up close beside her. 



ETHEOSTOMA OBEYENSE Kirsch 



Kirsch, 1890 (1892), Bull. U. S. Fish Comm., X, 292. 

 B., I, 78; J. & E., I, 1092; L., 29. 



Length 2 inches; body long and low, depth 5.6 to 6; greatest width about 

 34 greatest depth of body; depth caudal peduncle 2.2 to 2.4 in its length. 

 Color (in preservative) light brownish olive, much and rather finely blotched 

 with darker; back with 6 or 7 ill-defined cross-blotches; sides with 10 or 11 

 irregularly shaped dark spots along lateral line, often obscure; a dark spot on 

 cheek behind eye; suborbital streak faint or wanting; cheeks, opercles, and 



* The frequency ratios for the three sections are, for E. jessice .5-3, 1.46, and 1.02 for north- 

 em, central, and southern Illinois, and for E. cceruleum, 1.30, .42, and 1.28, respectively. 



