ON A CESTODE FROM DACELO GIGAS, BODD. — JOHNSTON. 249 



ventrally to both excretory vessels and the longitudinal nerve, 

 it enters the posterior end of the cirrus sac. 



This sac is thick-walled and muscular. It does not contain a 

 vesicula seminalis, but that part of the vas deferens which lies 

 within it, is again considerably coiled. In some segments the 

 sac was parti) 7 everted, resembling a short cylinder fifty-seven li 

 long by fifty fx broad ; and in one case (PI. lxx., fig. 4) the cirrus 

 seen projecting under compression at the end of the cylinder was 

 as a delicate transparent tube twenty-eight fx long by eight /x in 

 diameter. There was no trace of spines on it. There is a strong 

 sphincter at the external opening of the cirrus sac. 



The vagina is a delicate tube lying immediately behind and 

 below the vas deferens, the com se of the two ducts being generally 

 parallel. It opens externally into the genital cloaca just behind 

 the cirrus sac. in mature segments the vagina proceeds inwards 

 for h short distance ventrally to both excretory canals, becoming 

 gradually enlarged to form the elongated, thin-walled, pyriform 

 receptaculum seminis. Masses of sperms were present in the 

 structure. From its inner broad end there courses inwards and 

 backwards a narrow somewhat coiled tube, the fertilisation duct, 

 which possesses well-developed walls. The common oviduct 

 enters this duct, the ova become fertilised here and are carried 

 onwards to receive the secretions from the vitelline and shell 

 glands before entering the uterus. 



The ovary is a small organ situated in the anterior part of the 

 segment, at about its middle, though in young proglottids, it is 

 nearer the edge bearing the genital pure. It is not distinctly 

 bilobed, but consists of a number of short tubular glands slightly 

 divided into two masses. The products are discharged ultimately 

 into the short common oviduct. This joins the fertilising duct. 

 I could not detect paired oviducts. The ovary, as a whole, is 

 rather rounded, extending dorso-ventrally as well as posteriorly, 

 the common duct being surrounded by it during most of its 

 course. 



The vitelline gland is small, slightly bilobed and traverse])' 

 elongated. Its duct joins the fertilising duct after the union of 

 the oviduct with the latter. The shell gland is very small and 

 not easily distinguishable. It appears to me to lie between the 

 vitelline gland and the ovary. The whole female complex is so 

 small and crowded that the details are not as satisfactorily 

 followed out as I would wish, 



It seems as if the uterus arises as a tube, the continuation of 

 the fertilising duct. This gives off very numerous, narrow, 

 branching diverticula, which come to surround the testicular 



