344 



ORGANS OF NUDIBRANCIIIATA. 



The course of the reproductive process may be supposed 

 to be as follows : The spermatozoa mature before the ova, and 

 gradually collect in the ampulla ; during copulation this mass of 

 spermatozoa is transferred to the receptaculum seminis of the 

 other copulating Doto. From the receptaculum the spermatozoa 

 wander into the fertilizing chamber, and there meet the ova which 

 have matured in the meantime ; this migration of the spermatozoa 

 will be found fully discussed by Brueil (6), and, although it is 

 questionable whether such a migration takes places in all Nudi- 



Fig. 3- 



branchs, the structure of the genitalia of Doto makes it seem very 

 probable for this animal. After fertilization, the eggs are passed 

 out, receiving a coating of slime as they pass the openings of 

 the sluice reservoirs. 



Other Genera. 



Other genera studied were : — Tritonia pichcia and Cory- 

 phella rnfibranchiaUs (specimens, named from the Board of 

 Fisheries, Plymouth) ; Calma cavolinii and Rizsolia pcrcgrina 

 (determined by myself at the Aquarium, Naples) ; Bcrghui sp. 

 (from Dr. Ludwig Bruel, Halle-am-Saale). 



