271] PROTEOCEPHALIDAE—LA RUE 271 



proglottid. There is no genital papilla. The genital pore (Fig. 181) 

 leads into a small genital atrium into which both cirrus-pouch and 

 vagina open. The vagina always lies anterior to the cirrus-pouch and 

 its opening is also clearly anterior to the opening of the male ducts. 

 Monticelli notes a sort of sphincter muscle about the genital atrium 

 (Fig. 181). He states that this sphincter draws the opening of the 

 vagina and cirrus-pouch very closely together. 



The testes are spheroidal. They measure from 0.05 by 0.05 to 0.05 

 by 0.06 to 0.07 by 0.085 mm., number about 100 or even more, and are 

 situated (Fig. 95) dorsally in a field which covers the entire proglottid 

 except that region occupied by the ovary and by a narrow strip on either 

 lateral margin of the segment. There is no free median zone as Monti- 

 celli states and as he shows in his figure, reproduced (Fig. 186). His 

 statement that they are not numerous is incorrect. The testes (Fig, 94) 

 are outside of the inner longitudinal muscle layer, a condition which 

 does not occur in any species of the Proteocephalidae nor, so far as can 

 be ascertained by the writer, in any family of Tetraphyllidea. A careful 

 study of Braun's (1894-1900) great monograph on the cestodes gives no 

 reason for believing that this condition has been observed heretofore in 

 any order of cestodes. In the Pseudophyllidea he states definitely that 

 the testes occur in the medullary layer. He makes the same statement 

 for the Tetraphyllidea and the Cyclophyllidea. And as for the genital 

 organs in the Diphyllidea and the Trypanorhyncha he states that they 

 are as in the Tetraphyllidea. The location of the testes in this species 

 then is unique. 



The vasa efferentia have not been observed. The vas deferens forms 

 an elongated mass of coils which extends from the cirrus-pouch toward, 

 but not reaching, the mid-field. This mass of coils lies just a little poste- 

 rior to the cirrus-pouch and within the layer of inner longitudinal mus- 

 cles. The duct of the vas deferens is not of uniform diameter through- 

 out but is narrow in its beginning region then dilated and again con- 

 stricted just before entering the cirrus-pouch. With its swollen coils the 

 vas deferens functions as a vesicula seminalis. The cirrus-pouch (Fig. 

 181) is somewhat muscular, its muscles best developed near the outer 

 end. Its length varies from 0.286 to 0.315 and even to 0.340 mm. and 

 its breadth from 0.094 mm. in the longer pouches to 0.105 mm. in the 

 shorter ones. The pouch tapers frequently to a blunt point at the 

 inner end and is usually broadest near its opening. Its length goes 5 to 

 6 or 6^ times into the proglottid breadth. The ductus ejaculatorius 

 (Fig. 181) is slender and has thin walls. It makes numerous intricate 

 coils before passing over into the cirrus. The protruded cirrus has not 



