149] PROTEOCEPHALIDAE—LA RUE 149 



0.050-0.065 mm. in diameter, which are sometimes rendered polyhedral 

 by pressure of adjacent testes. They number from 75 to 100 and are 

 crowded into one or two irregular layers in the space between the 

 vitellaria and anterior to the ovaries. The vas deferens (Fig. 183) 

 forms a large mass of coils beginning in the mid-field of the proglottid 

 and reaching to the cirrus-pouch. A large part of this mass of vas 

 deferens is posterior to the cirrus-pouch. The cirrus-pouch (Fig. 183) 

 is a large pyriform structure, heavily muscled with both longitudinal 

 and circular muscles. Its larger and inner end is attached by heavy 

 muscle strands to the dermo-muscular sac. It measures 0.40-0.50-0.65 

 mm. long by 0.150-0.230 mm. in maximum breadth. The ratio of its 

 length to the proglottid breadth varies from 2:7 to 2 :5. When it is 

 protruded the cirrus is long and slender, a little larger at the base than 

 at the tip but when within the cirrus-pouch the basal part of the cirrus 

 has a broad lumen. This sharply defines the cirrus from the slender 

 ductus ejaculatorius which forms an intricate mass of coils. 



The vagina (Fig. 183) always lies anterior to the cirrus-pouch. 

 Very near its opening the vagina dilates markedly and in this region 

 it is provided with a thick and powerful sphincter vaginae measuring 

 about 0.030 mm. thick by 0.300 mm. long. This prominent sphincter 

 surrounding the greatly dilated vagina renders the latter a striking 

 feature of the proglottid and makes a valuable diagnostic character for 

 the species. At the inner limits of the sphincter the vagina contracts 

 sharply and beyond the constriction it again dilates. Here its inner 

 surface is weakly ciliated. Anterior to the ovary the vagina may 

 describe a few coils before it passes into that portion of its length which 

 is differentiated into a small receptaculum seminis. Entering the inter- 

 ovarial space the vagina describes a few coils and then discharges into 

 the oviduct. The ovary (Fig. 184) is situated in the posterior part of 

 the proglottid. It is bilobed, each lobe being thick, broad and somewhat 

 club-shaped. The lobes extend laterad to the vitellaria. From the mid- 

 piece of the ovary arises a muscular organ, the oocapt or gulping organ. 

 From the oocapt arises the oviduct which after making one or more 

 coils is joined by the vagina. From this point the oviduct extends to 

 the ootype. Just as it enters the ootype the oviduct receives the common 

 vitelline duct which has been formed by the union of the paired vitelline 

 ducts arising in the posterior part of the vitellaria. 



The ootype is surrounded by the so-called shell-glands, the indi- 

 vidual cells of which are long and clubshaped. The ootype discharges 

 into a somewhat muscular duct known as the uterine passage which 

 extends anteriad passing the ovary on the dorsal side. It discharges into 

 the uterus from the dorsal side of the latter at a point about 0.080-0.110 



