156 FISHES OF ILLINOIS 



torn, drawn from 69 collections only, give us no evidence of 

 any definite choice, the corresponding coefficient being 1.01. The 

 species has been taken by us 208 times, from 136 Illinois locali- 

 ties. Outside the state it is distributed far and wide, from the 

 Great Lakes and the smaller lakes of New York to the Roanoke 

 River on the Atlantic coast and to the Tombigbee in Alabama, and 

 westward through the Ohio Valley to the Arkansas and the tribu- 

 taries of the Missouri in Kansas and Missouri. Notwithstanding 

 this wide-spread general occurrence, its distribution in this state is 

 somewhat peculiar, as shown by the fact that, although we have col- 

 lected it throughout the state, our records of its occurrence are sev- 

 eral times more numerous from the eastern half of Illinois than from 

 the western. It is one of the species which enters freely the lower 

 Illinoisan glaciation, and is, indeed, much more abundant southward 

 than in the northern parts of the state. Its area of greatest pro- 

 portionate abundance in our collections is that containing the Big 

 Muddy, the tributaries of the Wabash, and the small rivers and 

 creeks of extreme southern Illinois. 



Females bursting with eggs have been taken about the first of 

 June, together with spring males with heads profusely covered with 

 •small tubercles of a peculiar whitish tint. Tuberculate males have 

 occurred, indeed, in our collections from the middle of May to 

 August 1. 



Genus ERICYMBA Cope 



Body elongate, little compressed; muzzle broad; interorbitals, sub- 

 orbitals, and dentaries containing greatly developed mucus channels, 

 which appear externally as distinct transverse vitreous streaks; no barbel; 

 premaxillaries protractile ; teeth 1 , 4-4, 1 or 4-4, without grinding surface, 

 hooked; intestine short; peritoneum silvery; dorsal rays 8; anal 8; scales 

 about 35; lateral line continuous. Size small. One species known. 



ERICYMBA BUCCATA Cope 



(silver-mouthed minnow) 



Cope, 1865, Proc. Ac. Nat. Sci. Phila., 88. 



G., VII, 185; J. & G., 204; M. V., 62; J. & E., I, 302; N., 45; J., 61; F., 76; L., 18. 



Small, pale silvery to straw-colored fishes with an elongate and de- 

 curved snout, sufficiently distinguished from all other Illinois Cyprinides 

 by the externally visible mucus channels in the infraorbital and lower jaw- 

 bones. Length 3 to 4 inches ; body fusiform, rather elongate and little com- 

 pressed, and the back not much elevated; profile not angled at nape, 

 being a gentle convex curve from base of dorsal to tip of snout ; depth 4 . 1 



