ORGANS OF NUDIBRANCIIIATA. 



345 



Of these animals the Calma and the Coryphclla have repro- 

 ductive organs very similar to those of Doto fragilis. 



The Coryphclla differs only in having a very large, muscular 

 penis, with no definite shape, and in having no ductus ejacula- 

 torius ; the fertilising chamber is small and more or less round. 



The Calma has a penis similar to that of Doto, but the 

 prostata is present simply as a thickening of the walls of the 

 penis-chamber at the base of the penis itself; there is no ductus 

 ejaculatorius. The fertilising chamber is a small roundish sac 

 opening into the albumen gland, so that the fertilised eggs have 

 to pass through a portion of that gland on their way to the 



Fig. 4. 



exterior. The albumen and slime glands are not supplied with 

 reservoirs as in Doto. 



It is not quite clear that the various sacs which I have called 

 receptacula seminis do not at the same time act as bursse. The 

 anatomical structure of the organs in the case of Doto makes it 

 quite possible that this could be so; even in Calma the receptacu- 

 lum may at the same time be the bursa copulatrix, although the 

 absence of a long ductus ejaculatorius makes it somewhat im- 

 ])robable. In the case of Coryphclla it seems impossible that the 

 thick, muscular penis, with no ductus ejaculatorius, could be intro- 

 duced into the receptaculum through the long, thin tube leading 

 into the latter. 



