2 University of Michigan 



mm. long. The four suckers small, measuring 0.051 to 0.087 

 mm. in diameter, with the average of ten about 0.071 mm. 

 Fifth sucker functional, about 0.034 mm. in diameter. First 

 proglottids broader than long, measuring about 0.32 to 0.48 

 mm. by 0.012 to 0.050 mm. Mature proglottids broader than 

 long or nearly quadrate, 0.446 by 0.361 mm. to 0.896 by 0.245 

 mm. Ripe proglottids differing greatly in length and breadth, 

 varying from 0.882 mm. broad by 0.782 mm. long in ovigerous 

 proglottids to 0.446 mm. broad by 1.3 16 mm. in old proglottids 

 nearly ready to be dehisced. Genital pore marginal, situated 

 at 0.3 to 0.46 of the length of the proglottid from the anterior 

 end. Testes numerous, about 60 to 90 in each proglottid, ap- 

 parently arranged in one layer filling the space anterior to the 

 •ovarian lobes. Coils of vas deferens voluminous, extending to 

 the mid-field of the proglottid. Cirrus-pouch short and rela- 

 tively broad, 0.099 to 0.133 mm. long by 0.039 to 0.056 mm. 

 broad, extending but little past the vitellaria. Cirrus and duc- 

 tus ejaculatorius forming two or three coils within the cirrus- 

 pouch. Ovarian lobes slender and long in much contracted 

 proglottids. thickened, rounded or even bent back on them- 

 selves in some elongated proglottids. Vitelline follicles rela- 

 tively coarse, closely packed together; vitellaria voluminous. 

 Uterus with 7 to 9 lateral pouches on either side in less distend- 

 ed ovigerous proglottids, and as many as 15 or 16 in old 

 elongate proglottids. Vagina anterior or slightly dorsal to cir- 

 rus-pouch. Sphincter vaginae small or lacking. Embryos of 

 uterine eggs about 0.015 mm. in diameter. 



Habitat : Adult form in intestine of Perca Havescens 

 (Mitch.) and AuihlopUtes rupcstris (Rafinesque). 



Distribution: Lakes Mendota and Monona, Wisconsin; 

 Hubbard Lake, Alcona County, and Douglas Lake, Cheboy- 

 gan County, Michigan. 



