178 Wisconsin Academy of Sciences, Arts, and Letters. 
Cystidicola serrata (Wright) 
Sixteen specimens were found in the intestine of a sheepshead 
caught in Lake Pepin. 
Cystidicola sigmatura (Leidy) 
A single specimen was found in a mooneye caught in Lake 
Pepin. This species was abundant in the swim bladders of the 
ciscoes in Lake Michigan, occurring in all the species except the 
long jaw. 
Dacnitoides cotylophora Ward & Magath 
This species was often common in the yellow perch, occurring in 
the intestine of that species in all of the five lakes studied except 
Pepin. It was also found in the intestines of other fishes as follows: 
Lake Pepin: channel cat; Green Lake: speckled bullhead; Lake 
Michigan: black bullhead, sucker. 
Cysts of this species were also found among the viscera of a cisco, 
Leucichthys johan7iae (Wagner), in Lake Michigan. 
Haplonema immutatum Ward & Magath 
Found in the intestine of a dog fish in Lake Pepin. 
Histerothylacium hracJiyurum Ward & Magath 
Pound in the intestines of the largemouth black bass and yellow 
perch in Lake Geneva. 
Icthyonema cylindraceum Ward & Magath 
Cysts of this species were common in the liver and peritoneum 
of many fishes. Occurrence: Lake Geneva: smallmouth black bass, 
yellow perch; Lake Mendota: speckled bullhead, Johnny darter, top 
minnow, cisco, largemouth black bass, shiner —Notropis heterodon 
(Cope), yellow perch, white bass; Lake Pepin: black bullhead; 
Green Lake: rock bass, top minnow, yellow perch, blunt-nosed 
minnow; Lake Michigan: Johnny darter, Iowa darter, pumpkin- 
seed, yellow perch, blunt-nosed minnow. 
Oxyuris sp.? 
A mutilated specimen, apparently belonging to this genus, came 
from a blue-gill caught in Lake Pepin. 
