676 Wisconsin Academy of Sciences , Arts , and Letters . 
ON A NEW MYXOSPORIDIAN, HENNEGUYA 
WISCONSINENSIS , N. SP., FROM THE 
URINARY BLADDER OF THE 
YELLOW PERCH, PERCA FLAV- 
ESCENS 
JAMES W. MAVOR AND WILLIAM STRASSER 
University of Wisconsin 
The myxosporidian to be described was found in the 
uninary bladder of a yellow perch, Perea flavescens , caught in 
Lake Mendota, Wisconsin, and examined on April 15th, 1915. 
The fish was a male 22 cm. in length. After the discovery of 
the parasite in this specimen, the urinary bladders of twelve 
other yellow perch were carefully searched in the latter part 
of April and May for the myxosporidian, but without suc¬ 
cess. The latter fish were, however, all under 15 cm. in 
length. 
Diagnosis of Henneguya wisconsinensis n. sp. 
The myxosporidium (Fig. 1, a , 5, and c) is usually elon¬ 
gated and has the general form and shape of a limax amoeba. 
It may reach a size of 300 x 70 //. Ectoplasm and endoplasm 
are clearly to be distinguished. The pseuopodia are lobose. 
The pansporoblast contains two sporoblasts. 
The spores (Fig. 3, c) are ovoid, bilaterally symmetrical, 
and have a bifurcated caudal filament extending from the 
posterior end. The two polar capsules are situated near to¬ 
gether in the broader, anterior end. The filaments can be 
seen in the fresh state within the polar capsules as spirals. 
