22 Art. 8.— S. Goto and Y. Matsudaira : 



its last loop it is usually more or less notably expanded and passes 

 into the metraterm, which proceeds thence almost straight for- 

 wards on the left side of the penis sac, and at the level of the 

 common genital pore makes a sudden turn towards it and opens 

 into the ventral portion of the genital atrium. The uterus con- 

 tains but few eggs at a time, about 5-10 all told. The egg is 

 asymmetrical and is provided at one pole with a very short stalk- 

 like process, the operculum being found at the other pole. The 

 dimensions of the egg as measured in the three different aspects 

 shown in fig. 5 are (a) 78x39/*, (b) 78x41//, (c) 47x37^. The 

 shell is dark brown in older eggs. 



The oviduct receives at a short distance from the insemina- 

 tion chamber the opening of the seminal receptacle. This is a 

 comparatively large, flask-shaped vesicle lying just in front of the 

 right testis, on the dorsal side of the vas deferens and the seminal 

 vesicle and is nearly always filled with sperm. The neck is nearly 

 as long as the body, and communicates just before opening into 

 the oviduct with the Laurer's canal. This is a tolerably long 

 canal with a thick cuticular wall and a narrow lumen and proceeds 

 from the point of its origin dorsalwards, and after making a few 

 light windings on the way, opens on the dorsal surface of the 

 body at some distance to the left of the median line. 



The vitellarium lies between the oral sucker and the penis 

 sac, in the superficial part of the parenchyma, all around the body 

 as seen in a cross section, therefore enveloping the alimentary 

 system on nearly all sides (fig. 1). The lobes are relatively small 

 and on the dorsal side they extend from a little behind the oral 

 sucker to about the hind end of the penis sac and do not show 

 any regular arrangement; but in some examples the paired condi- 

 tion is suggested by the presence of a median portion free of the 

 lobes. On the ventral side the lobes are arranged roughly in the 

 shape of an X, with the point of intersection on the ventral side 

 of the œsophagus and with an irregular connection between the 

 two arms at the front end ; the anteroposterior extension nearly 

 coinciding with that of the dorsal portion but stopping a little 

 shorter behind at about the level of the genital pore. In the 



