BY S. J. JOHNSTON. 283 



paratively large " shell- g] and " lie. Laurer's canal is long, cours- 

 ing along beside the inner testis, right up to the middle line of 

 the body, where it opens on the dorsal surface. 



The uterus, a comparatively narrow tube, runs to the left in a 

 series of small waves, in front of the inner testis, behind the 

 ventral sucker and behind the cirrus-sac, between that organ 

 and the posterior loop of the left intestinal limb. In the middle 

 part of its course, it is considerably dilated to form the recepta- 

 culum-seminis-uterinum, which, in most of the specimens, is filled 

 with considerable masses of spermatozoa. There is no "recepta- 

 culum seminis." The vagina opens into the posterior side of the 

 common genital chamber, just near the male opening. The 

 follicles of the yolk-glands vary from pear-shaped to tubular, and 

 average 0*051 mm. in width. These glands are very extensively 

 developed and widely distributed over the body, filling up the 

 space between the intestinal limbs and the various borders of 

 the body. The region round the suckers, however, is compara- 

 tively clear of them, and so also is the region near the genital 

 opening. 



The follicles also extend inwards beyond the intestinal limbs 

 to a slight extent, especially behind the cirrus sac, and on the 

 extreme right of the body, where, to the right of the outer testis, 

 they spread over the whole field. The yolk-ducts from the left 

 side run close to the loops of the intestinal limb, gradually con- 

 verging after passing the cirrus-sac, and joining to form a large 

 common duct a little to the left of the ventral sucker. This 

 common duct is joined near the yolk-reservoir, on the one hand 

 by a duct which runs along from the right near the anterior limb 

 of the right intestinal limb, and, on the other hand, by a duct 

 which is itself formed by the confluence of two ducts coursing 

 along near the posterior loop of that intestinal limb, from the 

 right and left (Fig.l,Y.d). 



The eggs are comparatively few in number, oval in shape (Fig. 

 la), thin-shelled, of large size, 0*105 x 0077 ram. They vary 

 somewhat in size, the smallest being 0096 x 0*069 mm., while 

 the largest was 0*111 x 0*079. The operculum is situated at the 

 narrower end. 



