TRITONIA PLEBEIA, 



Dr. Johnston now considers his Tritonia pulchra to be a variety of this, which is not 

 improbable, considering how much the species varies in colour,, though we have not seen a 

 specimen entirely agreeing with his description. We have more than once met with a lemon- 

 yellow variety, which may possibly be the Doris electrica of Pennant, his figure agreeing 

 better with the form of this species than of any other we are acquainted with. 



Tritonia plebeia is not by any means an active animal. It is very generally distributed 

 in the British seas, and is one of the commonest deep-water nudibranchs of our eastern 

 coast. Professor E. Forbes found it in the iEgean, but it has not yet been noticed on the 

 western shores of Europe. Probably it may have been overlooked, from its similarity to the 

 young of the larger species. 



We have not often met with the spawn of this species. It is usually deposited on the 

 stems of corallines, and forms an irregular waved or festooned mass, the spiral nature of 

 which it is not easy to trace. When deposited on a flat surface, however, it assumes a 

 regular waved spiral, as we had the opportunity of seeing in an individual that spawned on 

 the side of a glass. The gelatinous thread is narrow and rounded, containing numerous 

 eggs, arranged about five abreast throughout. This individual spawned in October, but 

 we have also met with the spawn in May. 



Figs. 1, 2, 3. Tritonia plebeia, in different positions. 



4. A branchial plume more highly magnified. 



5. A tentacle very highly magnified. 



6. Spawn. 



7. A portion of the same highly magnified. 



