552 liKi'oirr ok tommissioner of fish and fisheries. 



The duct iVoin the j;cnn j;Iiiiid leaves that or<>au oii its jjostero-dorsal 

 side. Soon after leaving- the glaixh it enlarges for a. short space and 

 appears t> be lined in the enlarged jtortion with cilia. 



The vagina opens immediately behind the cirrus in a common genital 

 pore. In longitudinal sections parallel with the ventral surface and near 

 the exterior it appears as a simple transverse slit smaller than the male 

 orifice. The vagina pursues a somewhat tortuous course for a short 

 distance behind the external opening, during which time it lies near the 

 ventral surface. It then dips into the central region of tlie body and 

 passes along the median region on the dorsal side of the germ gland. 

 It enlarges at one point into a kind of seminal re(!eptacle (Fig. 13, r). 

 It appears to unite with the germ duct near the posterior edge of the 

 germ gland and on its dorsal side. 



The common duct formed by the union of the germ duct and vagina 

 soon receives ducts from the vitelline glands. The common duct thus 

 formed, and which is the beginning of tlu; uterus, functions as a shell 

 gland. In Fig. 13, o, o are ova which lie in the vicinitj^ of the shell 

 gland. See also Fig. 1-4 n' and the ideal sketch. Fig. 15 s(j. 



The product of the vitelline glands is added in the shape of small 

 globules of protoplasmic matter. These masses do not, at least imme- 

 diately, unite, and on that account the ova, even in the beginning of 

 the uterus, have the appearance of undergoing segmentation. In some 

 cases I observed ova that a])peared to be in the X)rocess of formation. 

 The shell was exceedingly thin and weak, and among the numertms 

 non-nucleated masses, products of the vitelline gland, could be distin- 

 guished the nucleated germ cell (Fig. 12 a). 



The uterus lies dorsally in the posterior part of the body. It is a 

 voluminous organ and when full of eggs occupies the greater jiart of 

 the body behind the cirrus bulb (Fig. 14 v). It is on account of the 

 accumulation of eggs in the uterus that the posterior surface of the 

 body is raised into irregular elevations (Figs. 1, 3, 7, 8). The uterus 

 begins behind the ovary and appears to originate from the continence 

 of the vagina, germ duct, and vitelline ducts. The first folds in sec- 

 tion inesent a reticulated appearance and contain numerous ova which 

 have thin and membranous shells. These ova are very irregular in 

 in their outline and are invariably colla])s<Hl. Both shell and contents 

 stain deeply with carmine. The ]ierfect ova have shells that resist the 

 action of the staining fluid. 



From its origin on t he postero-dorsal side of the germ gland the uterus 

 proceeds by numerous folds anteriorly in the direction of the cirrus 

 bulb. It appears to terminate, in the older specimens, in a pore imme- 

 diately behind the cirrus, in close proximity with the vagina. 



The ova are comparatively large, being 0.00 to 0.005 mm. in length 

 and 0.03 to 0.035 nun. in breadth. The globular masses of which their 

 protoplasmic contents are for the most part made up are 0.01 mm. and 

 over in diameter. 



