280 EliNEST WARREN. 



shell-gland (.sTi. gl.), consisting of large elongated glandular 

 cells. The yolk glands {t/L gl.) are fairly numerous, and 

 cluster around the gut-c^eca, but they do not extend beyond 

 them anteriorly. The uterus is narrow at its commencement, 

 but it soon widens aad forms a thin-walled tube, which is 

 convoluted to only a very slight extent, and then opens into 

 a muscular vagina with a crescentic external aperture 

 (Fig. 11, 0. v.). The uterus lies wholly in front of the testes, 

 and is exceptionally short when compared with the uteri of 

 the majority of Distomids. 



Nervous System. — On each side of the pharynx there is 

 a ganglionic enlargement (Fig. 11, n. sy.) ; these are con- 

 nected together dorsally by a nerve-band, but ventrally there 

 appears to be no commissure, and hence there is not a com- 

 plete nerve-collar around the pharynx. The nerve-strands 

 passing from the ganglia are typical in their arrangement. 



Excretory System. — The flame-cells tend to be situated 

 towards the periphery of the body, and they are very few in 

 number. In Fig. VI is shown one of these structures : the 

 nucleus is very large, and the flagellum, showing its com- 

 posite structure by being very distinctly striated longitudi- 

 nally, comes off directly from it: an intermediate piece {b. ^i.), 

 doubtless equivalent to the basal knobs of cilia, is clearly 

 visible. The cytoplasm of the cell is not readily separable 

 from the surrounding parenchyma. 



The flame-cell leads into a convoluted intra-cellular tube 

 {ca2^.). The tubes open into a slightly wider duct,Avhich also 

 appears to be intra-cellular. There are only two of these 

 ducts, a right and left, and they run inwards towards the 

 excretory bladder (Fig. II, m. d.). 



The excretory bladder is of very great size, being about 

 one half the length of the body. It is a muscular sac lined 

 internally by very large cells which generally contain 

 several nuclei. The cells are set on a basement membrane, 

 and their development is variable in different specimens, and 

 frequently they are placed separately from one another, so 

 that they do not constitute a distinct and continuous cpi- 



