Notes on South African Mollusca. 



Ill 



system found in Melampus. It differs, however, from all three in 

 having a number of muscle fibres inserted into the penis half-way 

 down from the external aperture. 



The female reproductive system appears to be considerably 

 simpler than in any of the three other genera, and, if the author's 



FIG. 3. 



Marinula tristanensis. Genitalia. (2 x a3 Binoc. Zeiss.) 



a. Penis, ft. Penis muscle, c. Vas deferens ; c', continuation of same. 

 d. Accessory penis muscles. e. Vagina. /. Hermaphrodite duct. g. Gonad. 

 ft. Spermatheca (?). 



interpretation is accepted, somewhat specialized, as the vas deferens, 

 instead of splitting off the sperm oviduct, has become completely 

 separated from it and issues from the base of an accessory organ * 



* This organ may possibly be an accessory glandular structure. If it is ulti- 

 mately proved to be the spermatheca, then the absence of other accessory organs in 

 the female generative system compares strangely with the condition seen in 

 Melampus, Phytia, &c. 



