NOTROPIS 153 



distributed throughout the state in fairly equal ratio, although 

 less abundant in the Illinois, the Kaskaskia, and the Big Muddy 

 than in the other stream systems. It is one of the small number 

 of species which we have found present in the Michigan drainage 

 in larger ratio (1.96) than in any other section. In its continental 

 distribution it is, on the whole, a northern species, its general 

 area extending from the St. Lawrence and Lake Champlain 

 through the Great Lakes to the northern shore of Lake Superior, 

 the Red River of the North, and the Saskatchewan, and through 

 the Ohio Valley to Tennessee and the Washita River in Kansas, 

 and up the tributaries of the Missouri. 



It moves and feeds in large schools, thousands being fre- 

 quently seen together near the surface. The food of those exam- 

 ined by us (18 specimens, all from the northern part of the 

 state) consisted principally of insects, nearly two thirds of which 

 were terrestrial species, and the remainder chiefly case-worms 

 and larvae of day-flies. Six of the specimens had, indeed, eaten 

 insects only, and these made 90 per cent, of the food of two 

 others. Three taken from Peoria Lake in October had eaten 

 only Entomostraca, which amounted, in fact, to the unusual 

 ratio of 22 per cent, of the food of the whole group. A single 

 specimen had taken about 40 per cent, of its food from the 

 thread alga?, and a minute fish had been eaten by another. 



Females greatly distended with eggs and apparently about to 

 spawn have been collected by us from the middle of May to the 

 first of June. The sexual differences are slight, and we have 

 seen no tuberculate males. 



NOTROPIS RUBRIFRONS (Cope) 



ROSY-FACED MINNOW 



(Map XLIV) 



Cope, 1865, Proc. Ac. Nat. Sci. Phila., 85 (Alburnus). 



G., VII, 255 (Leuciscus); J. & G., 202 (Minnilus rubrifrons and M. percobromus) ; 



M. V., 61 (dilectus); J. & E., I., 295; N., 47 (Minnilus); J., 60; F., 76 (dinemus, 



part); L,., 18. 



The smaller size, darker and less silvery coloration, shorter and deeper 

 body, longer head, longer snout and maxillary, and smaller eye, as well as 

 the dense tuberculation and flushed color of the head and predorsal region 

 in spring males of this species, will serve to distinguish this from the last 

 species described. Length 2% inches; body moderately elongate, back little 

 elevated; caudal peduncle slender, its depth 2.4 to 2.8 in its length; depth in 

 length 4.8 to 5.8. Color of upper parts rather dark olive, the scales dark- 

 edged; sides silvery above and below the dark, to almost black, lateral band; 



—19 F 



