84 ILLIXOIS BIOLOGICAL MONOGRAPHS [84 



1.02 mm.; 0.68 by 0.85 mm. The end-proglottid is triangular in out- 

 line, the posterior end being rounded. It is 0.425 mm. broad by 0.476 

 mm. long. Apparently it is functional. No excretory pore could be 

 seen at its posterior end. Of the proglottids Zschokke wrote: "Les 

 premiers articles sont courts, deux a trois fois plus larges que longs. 

 Les suivants deviennent carres et les derniers sont ordinairement plus 

 longs que larges. L' article terminal est arrondi en arriere. Les bords 

 des proglottis ne sont pas bombes; leurs angles sont tres peu emousses. 

 L 'animal ne presente ainsi point de crenulure; il a 1 'aspect d'un 

 niban." 



The genital opening which is situated near the middle or slightly 

 anterior to the middle of the lateral margin of the proglottid alternates 

 irregularly. There is no genital papilla. The testes (Figs. 75, 77) are 

 nearly round or at times slightly compressed. They measure 0.063- 

 0.079 mm. in diameter and they are situated in two partial layers 

 which cover the entire field betweeq the vitellaria anterior to the ovary. 

 Their number is from 55 to 60. The vas deferens forms a small com- 

 pact mass of coils in the midfield of the segment. The cirrus-pouch 

 (Figs. 75, 76, 77) is long, quite slender, smooth in outline or at times 

 somewhat constricted near the inner end by the contraction of circular 

 muscle fibers. The cirrus-pouch measures 0.370-0.425 mm. long in ripe 

 proglottids, 0.265-0.292 mm. long in a proglottid with few uterine eggs 

 and 0.228-0.265 mm. in mature proglottids where the cirrus is being 

 protruded. Its breadth is about 0.070-0.085 nmi. It extends from 5/11 

 to ^ across the proglottid breadth or in some cases it may extend 

 slightly past the middle. The cirrus is straight and slender. When 

 protruded it may extend aboat 0.1 mm. past the margin of the segment. 

 The protruded cirrus is slender or, if but slightly protruded, conical. 

 The ductus ejaculatorius is straight and of the same size as the cirrus 

 of which it really forms a part. 



The vagina opens into the conmion genital sinus apparently ante- 

 rior to the cirrus-pouch. Near its opening it possesses a small sphincter 

 vaginae. The course of the vagina is slightly anteriad then posteriad 

 and mesad in a long arc which crosses the cirrus-pouch near the middle 

 of its dorsal side. Its entire course into the interovarial space has not 

 been traced. A receptaculum seminis has not been observed. The 

 ovary is posterior and is bilobed, but in nearly mature proglottids 

 the mid-piece may not be visible. The lobes (Fig. 75) may appear 

 as more or less irregular quadrate bodies in the posterior comers of the 

 segment. In such a condition they resemble the ovaries which Zschokke 

 delineated. His figure is reproduced (Fig. 149). In more mature and 

 ripe proglottids the lobes of the ovary are smoother in contour (Figs. 



