119 



by one of the specimens, the hitter consisted wholly of seeds of 

 various pi mts fallen into the water. Eighty per cent, of the food 

 of two of the specimens, and twenty per cent, of that of a third 

 consisted of such seeds ; ratios evidently too large to have been 

 taken Rccidently. Two of the specimens had eaten Planorbis. and 

 all had eaten insects, which made about forty per cent, of the 

 food; terrestrial species, including spiders, making twelve per cent. 

 Among the aquatic forms were Chironomus larvae, Hjdrophihdee, 

 and larvcB of Ephemerid!i3. the latter eleven per cent, ('rustacea 

 were a fifth of the food, chiefly the abundant am phi pod, Allorclwstes 

 dentata. .Cypris and Candona were likewise noticed in considerable 

 quantity (seven per cent.), and a few specimens of various Cladocera 

 occurred. 



ZVGONECTES NOTATUS, Eaf. ToP MiNNOW. 



This species ranges in ponds and sluggish streams throughout the 

 State but is abundant southwards. Here it may commonly be seen 

 swimming slowly about in stagnant pools with tie head at the sur- 

 face of the water, as if interested in the phenomena of the weather, 

 or possibly watching for the appearance of terrestrial insects. The 

 alimentary structures are in all respects similar to those of Fundu- 

 lus, except that the intestine is possibly a little longer, being about 

 equal to the bead and body. The only striking peculiarity is the 

 depressed head, with the mouth placed at the upper angle and 

 opening obliquely upwards. This, with the surface swimming habit 

 of the fish has given rise to the supposition that it feeds largely 

 upon surface insects ; but I did not find this to be the case, as the 

 seventeen specimens studied contain no example of an insect of this 

 character. 



These specimens were taken from a considerable variety of situa- 

 tions throughout Central and Southern Iliinois, and at various times 

 of the year. The animal food amounted to about ninety per cent, 

 of the whole. Vegetation, almost wholly filamentous Algie, was 

 taken by ten of the specimens, but in such quantites by 

 various individuals as to make it certain that its presence 

 was not accidental. In one, for example, the intestine was 

 packed with these Alg.e to the exclusion of all otiier food, and in 

 three others this made more than half the whole. One specimen 

 had also eaten Wolffia. Mollusks (Physa) had been eaten by three, 

 and insects amounted to seventy-three per cent. Spiders and various 

 terrestrial insects made fully a fourth of the food. Philhydrus, taken 

 by three of the specnnens was reckoned at eight per cent. Corixa and 

 other aquatic Hemiptera amounted to eleven per cent, and larvaa 

 of Agrion to three. Crustacea was estimated at only six per cent. 

 They included Craiifioni/.r (irnciUs, and various Cladocera, Ostracoda, 

 and Copepoda. Among the Entomostraca recognized were Daphnia, 

 Chydorus, Pleuroxus. Acropeuis. Cypris, and Cyclops. Chiionomus 

 larvi^e were about one per cent., taken by only twt) of the specimens. 



