270 s. GOTO. 



and is divided into two by a deep incision. It is 0.22 mm. long. 



The general arrangement of the genital organs is essentially 

 similar to that of other species of the genus. The prostate 

 gland, the " vésicule séminale " of v. Beneden ['61, p. 35], is 

 oval, and in my specimen is entirely filled with a coarsely 

 granular mass, which stains deeply with carmin.'-' It opens into 

 the cavity of tlie penis by means of a very short duct traversing 

 the wall of the penis. The latter is comparatively long and 

 slender, and tapers gradually towards its apex. The vas de- 

 ferens undergoes convolutions similar to those found in other 

 species, and opens into the cavity of the penis at a point re- 

 moved from its proximal end about one third of its total length. 

 Van Beneden speaks of a ** vésicule de dépôt " at the point of 

 union of the two vasa efferentia ['61, p. 35] ; but in my speci- 

 men none conld be observed. The ootyp is very distinct and is 

 situated close to the penis ; the uterus is consequently very 

 short, and the oviduct proportionately long. 



One peculiarity of this species lies in the possession of a 

 single genital pore for both the common genital pore and the 

 vaginal opening of other species. In all the other species of this 

 genus, and in Phyllonella and Tristomum, the vaginal opening is 

 separated from the porus genitalis communis, and the union of 

 the two must be looked upon as of rather rare occurrence. 

 The vaginal canal presents near its posterior end a swelling re- 

 presenting the receptaculum seminis, from which a short canal 

 leads into the yolk duct. There was no yolk reservoir in my 

 specimen ; but this can not be regarded as proving its total 

 absence, since its formation is more or less dependent on the 

 accumulation of the yolk cells. 



* The specimen was stained witli acid carmin. 



