2G2 Mi: W. Nicoll on the 



than Miililmg has it. The peculiar inward bend of the 

 intestinal diverticula as thej^ approach tfie orenital sucker is 

 a constant feature, as is also their inward inclination at their 

 termination. The yolk-glands are, as a rule, somewhat more 

 voluminous than IMiihling represents them, and occasionally 

 form a continuous arch in front of the genital sucker. The 

 yolk-ducts pass along the anterior border of the testes, and 

 unite in a receptacle of variable size a little to the left of 

 the middle line. The receptacle is capable of comparatively 

 enormous dilatation. The fairly large, oval receptaculura 

 semiuis is situated immediately in front of the testes in the 

 middle line. The testes are much as Miihling represents 

 them and measure *18-'26 x '11-'16 ram. With regard to 

 the situation and shape of the ovary, my observations disagree 

 entirely with those of Miihling. In my specimens it occurs 

 on the right side of the body, directly in front of the right 

 testis. It has the form of a scalene triangle, the longest 

 side facing forwards ; the shortest side lies along the recep- 

 taculura seminis, while the third side is parallel to and almost 

 contiguous with the anterior border of the right testis. The 

 latter sides are regularly lobed, there being four or five lobes 

 on the side next the testis and two or three on that next the 

 receptaculura seminis. The lobes are not of great depth. 

 The anterior face is more even. The uterus has a character- 

 istic appearance. It makes first a short turn to the left, 

 then sti'etches across the body to the right side, whence it 

 bends back again to the left side, and turning forward 

 proceeds to the genital sucker. Its shape is therefore C^-like, 

 with two short turns at the ends of the limbs. It never 

 extends over the intestinal diverticula. In Muhling's figure 

 the uterus traverses the body four times. The ova are not 

 very numerous, light brown in colour, with a thick shell. 

 They are more pointed at one pole than appears from 

 Miihling's representation. Their size is ■034--037 X 'OlS- 

 •019 mm. 



Putting aside the possibility of error on Miihling's part, 

 which does not seem likely, only two alternatives remain : 

 we have here to deal with a case of " situs inversus " of the 

 ovary, which is not uncommon in certain species, or my 

 specimens must represent a distinct variety or species. To 

 elucidate the matter I examined more than fifty examples 

 and succeeded in finding one with the ovary on the left side, 

 the bend of the uterus directed towards the same side and 

 the yolk -receptacle on the right. Even then it did not 

 resfmble Miihling^s figure, for the ovary retained its charac- 

 teristic shape, the yolk-receptacle m as on the opposite side 



