518 



REPOKT OF THE COMMISSIONER OF FISHERIES. 



The kind of parasites and tlieir prevalence in the different parts of 

 the alimentarv tract were as follows: 



Every fish examined contained some parasites. Cestodes and nema- 

 todes were present in more than half, while Acanthocephala occurred 

 in but a single fish. It w^as noticeable that fish cauo-ht in April and 

 May were much freer from parasites than those caught in November. 

 The trematodes were nearly all Azygia tet'eticolle. One cestode was a 

 species of Proteocephalus. 



6. Pomoxis sparoides, calico bass. 



Three specimens of calico bass were caught during July in Lake 

 Wingra. They had plankton onh^ as food. The only parasites found 

 were two leeches, one on the tongue of one fish and one on the roof of 

 the mouth of another, and a few small cysts on the outer wall of the 

 stomach. 



7. Aml>lo2)lites rupestins^ rock bass. 



Sixteen rock bass were caught during ^Slay and July in Lake Men- 

 dota. The food, found in the 13 fish containing any, consisted of insect 

 larvEe in 2 and crawfish in 12. The specimens examined by Forbes (b) 

 were found to have eaten insect larvae" much ofteuer than the bass 

 from Lake ]\lendota. 



Three fish were without parasites. In the 13 in which they were 

 found the distribution was as follows: Trematodes in 1, nematodes in 

 3, and Acanthocephala in 12. Almost as noticeable as the fondness for 

 crawfish as food was the prevalence of Acanthocephala; the entire 

 absence of cestodes is also noticeable. 



8. Lepomis incisor^ bluegill. 



Specimens were taken in March, April, and July from Lakes Men- 

 dota and V\"ingra, Thirty fish were examined, 20 containing food, as 

 follows: 



Thirteen of the fish were entirelj" without parasites, as far as 'a gen- 

 eral examination showed, and the other IT contained the following: 



