18 RECORDS OF THE AUSTRALIAN MUSEUM. 



The cirrus is very long and slender and when at rest lies irregularly 

 and loosely coiled. It can be thrust out to a very considerable 

 degree, the everted portions actually reaching - 50 mm. in one 

 case observed, the width of the segment to which it belonged 

 being 092 mm. In the case of other cirri the length was much 

 less, but eversion was not complete. Each cirrus is thus a very 

 long delicate tube, its maximum breadth being 0054 mm. It 

 does not possess a basal enlargement like that found in D. injiata 

 and D. acuminata. Unlike these species and D. americana, 

 D. Jiavescetis shows the presence of a minute armature on the 

 cirrus. 



The female glands consist of a compact trilobed ovary lying 

 ventrally in the midregion of the segment and of a vitelline 

 gland, situated dorso-posterioily to it. The mature ovary extends 

 from the excretory vessels of the one side to those of the other, 

 being about 039 mm. in width. Of the three lobes, one lies 

 medianly in front of and between the other two which are lateral. 

 The median is smaller than either of the others. The yolk-gland 

 is either rounded or kidney-shaped and lies at the posterior edge 

 of the segment, its position being more dorsal than that of the 

 ovary. The vagina travels inwards immediately behind and 

 somewhat ventrally to the cirrus sac in a number of wide rather 

 closely arranged coils. Its general course is inwards and slightly 

 backwards until it opens into a spacious thin-walled receptaculum 

 seminis which extends inwards in mature segments to about the 

 middle of the ovary, as an elongate wide tube. It lies above the 

 excretory vessels and the ovary, and ventrally to the cirrus sac, 

 vesicula seminalis, and testes. Its position is at a slightly higher 

 dorsal level than that of the vagina. The uterus in mature 

 proglottids is a sac-like organ lying ventrally but occupying most 

 of the medulla between the excretory vessels of each side, except 

 in the anterior region of each segment where the male and 

 female ducts and reservoirs are situated. It also extends laterally 

 above the excretory vessels on the pore-bearing side but below 

 them on the opposite side of the segment. Thus the excretory 

 \tssels come to lie in a bay or groove formed by the uterus which 

 partly surrounds them. The mature eggs are from 090 to 

 0-107 mm. in length and from 0027 to 0031 mm. in breadth. 

 Kach end is somewhat bluntly pointed, while each extremity of 

 the inner shell is produced into a very prominent process. The 

 inner shell measures from 0.34 to 00G8 mm. in length by 

 about 001 6 mm. in breadth. 



