42 PROCEEDINGS OF THE NATIONAL MUSEUM vol.70 



from a low papillary eminence on the inner wall of the genital 

 cloaca. This eminence is densely covered with short spines (fig. 

 142). The cirrus is slender, filiform and smooth, about 0.25 mm. 

 in length. Its diameter at base is about 0.012, whence it tapers 

 slowly and uniformly to the tip. At a point 0.06 from the tip the 

 diameter is about 0.007, The cirrus-pouch is subcylindrical, and 

 extends nearly to the aporal excretory vessels. Its walls are thick 

 and muscular, and for a considerable portion of its length it acts 

 as a seminal vesicle. There is a capacious inner seminal vesicle, 

 which, at least in short adolescent proglottides, lies very close to 

 the cirrus-pouch, along the ventral side, and from a point near the 

 anti-poral end as far as the middle of the length of the pouch. The 

 testes are relatively large, 0.28 mm. in transverse section, one poral, 

 and two anti-poral (fig. 141). The vagina is tubular and leads by 

 a more or less meandering course, to a relatively capacious seminal 

 receptacle. The ovary, situated at the median line, is small, lobulate, 

 almost morula-like in its early stages of development. Coincident 

 with the degeneration of the testes the ovary increases in size, and 

 becomes broader than long. It is rather compact but lobulate, and 

 is made up of large cells. The vitelline gland is a small but con- 

 spicuous organ, distinctly lobed in some proglottides, more com- 

 pact in others. 



The two longitudinal muscle layers, while well developed, are not 

 very sharply marked off from each other. The outer layer is com- 

 posed of a large number of small fascicles of irregular size and 

 shape, which are confusedly placed as seen in transverse sections. 

 In transverse sections through the anterior end of a proglottis this 

 layer is close to the cuticle, but becomes separated from the cuticular 

 region in succeeding sections. Along the inner border of the muscu- 

 lar layer at intervals there are larger fascicles, sub-circular in sec- 

 tion. These fascicles represent the inner layer of longitudinal 

 muscles. The ventral excretory vessels are relatively large, and ap- 

 pear somewhat triangular in cross section. The dorsal vessels are 

 small and inconspicuous in the series of sections which was examined. 

 They are rather variable in position, being more or less displaced 

 by the large cirrus-pouch. The latter passes on the dorsal side of 

 the excretory vessels. 



Dimensions of different types of strobiles. 



Length 33. 00 



Diameter of scolex .35 



Diameter of sucker . 14 



Lengtti of rostellum .28 



Lengthi of lioolcs . 06 



Lengtli of proglottis near posterior end .08 



Breadth of proglottis near posterior end 1. 40 



