FOOD AND PARASITES OF SOME FRESH-WATER FISHES. 519 



Ccstodes 



Nematodes 



Acauthocephalii 



Stomach. 



Intestine. Rectum. 



Body 

 cavity. 



Leech in mouth, 1; cestode or nematode cysts in the liver, 6; cysts in mesentery, 1. 



9. Euponwtls giljhosus, common suh-fisli. 



Six specimens only were examined. Of these 5 contained food, 

 consisting- of insect larvse, snails, and small bivalves. One sun-fish 

 had no parasites; the other 5 contained each-a number of Acanthoce- 

 phala, encysted in the mesentery of 3 fish and mature in the intestine 

 of j:he other 2. 



10. M'ic7'0}yterns dolonileu, small-mouthed black bass. 



But .5 specimens were examined, all caug-ht during July in Lake 

 Mendota. One bass was free from food; in the stomachs of the other 

 4, crawfish were found. Cestodes were more abundant than any other 

 parasite, and were found in the stomach, body cavity, and ovary. 

 One species was Proteocephcdus amhloplites. Azygia tereticolle was 

 found once in the mouth and once in the stomach. Nematodes and 

 Acanthocephahx w^ere found in the intestine of 3 of the bass examined. 

 Encysted worms were found in the wall of the stomacb of one jBsh and 

 in the liver of another. 



11. Mlcrojyterus sahnoides, large-mouthed black bass. 



Nearly all of the fish examined w^ere taken from Lake Mendota. 

 Onl}' four were caught in Lake Monona and the same number in Lake 

 Wingra. Most of the specimens from Lake Mendota were caught in 

 the trammel net, and were taken on the southern shore near the mouth 

 of or just within a small creek, which, in this part, was from 3 to 5 feet 

 *in depth. The majority of the fish were caught in April or Ma}^ a few 

 only during July and August. To those already enumerated were 

 added 4 bass from Round Lake in the northern part of the state. A 

 careful study of the records failed to reveal an}^ differences in food or 

 parasites in the fish from the different lakes, except that the 4 from 

 Round Lake all had copepods on the gills, there being among all the 

 other fish but a single specimen so infected. 



Of the 42 fish examined, 29 contained food which could be recog- 

 nized. The other 13 showed nothing the nature of Avhich could be 

 distinguished. The following table gives the kinds of food found and 

 the number of fish in which each kind was present: 



