The Food of the Smaller Fresh- Water Fishes. 79 



The alinioiitarv canal is two or three times tlie lenartli of the 

 body, and the irill-rakers are fifteen in number and somewhat 

 more prominent than usual, those on the posterior part of the first 

 arch being about one-tliird the length of the corresponding fila- 

 ments. 



Only four specimens were studied, one from the Pecatonica 

 River at Freeport, and three from Otter Creek in Jersey County. 

 With this fish as with the preceding, about three-fourths of the 

 contents of t!ie intestine consisted of mud, the remainder beino- 

 almost wholly insects. These were partly terrestrial species, oc- 

 curring accidentally in the water, and partly aqiiatic larva' of Dip- 

 tera. The vegetable food of these specimens amounted only to 

 about one per cent., chiefly various unicellular Alo-ie. 



Hyborhynchus notatus, Raf. Blunt-nosed Minnow. 



This extremely abundant minnow occurs in streams and rivers 

 throughout the State, but has not been found by us in ponds. 

 Specimens were taken, however, in the small lakes of Northern 

 Illinois. 



The intestine is about two and one-half times the length of 

 the head and body. The irill-rakers are few, shoi't and thick, 

 being about one-fifth of tlie length of the corresponding filaments. 



Nine specimens were studied from all parts of the State, when 

 their food proved to be so uniform in character that further obser- 

 vations were deemed unnecessary. Mud made about eighty per 

 cent, of the contents of the alimentary canal, the remainder con- 

 sisting of unrecognizable vegetable debris, with a few filaments 

 of Alg;e. Undeterminable insects occurred in one, and a single 

 specimen of Cypris in another. 



Hyuognathus nuchai.is, Ag. Blunt-.tawed Minnow. 



This species is likewise generally distributed in rivers, creeks 

 and ponds, occurring in our collections from Galena to Cairo, and 

 at a great number of points intermediate. 



The alimentary canal in this genus is elongate, being about four 

 times the length of the body. The gill-rakers are few and rather 

 short, triangular in form, and about one-fourth to one-fifth the 

 length of their corresponding filanu'nts. 



Eight specimens of this species were dissected, with results in 



