HERMiEA BIFIDA. 



branchiae. The heart forms a swelling on the anterior part of the back, in front of which the 

 tubular vent is situated. 



This lovely nudibranch was long known only from the description of Montagu. More 

 recently it has been again brought to light by the indefatigable naturalists of Belfast ; but 

 during our researches on various parts of the coast, continued for several successive years, it 

 has never been our good fortune to meet with it. We had almost despaired of getting a 

 drawing from a living specimen, when our friend Mr. David Landsborough, Jun., fortunately 

 met with it near Edinburgh, and kindly sent us from thence the splendid specimen from 

 which our figures and description have been taken. This specimen was more than three 

 times the size of that described by Montagu, and appears in every respect to have been in a 

 much finer state of development. It was obtained along with two or three other individuals 

 of different sizes on a plant of Griffithsia setacea, gathered on the Black Rocks, Leith. 



Professor Loven, who has published an excellent description of this species in the 

 ' P roceedings of the Royal Swedish Academy,' informs us, that it is gregarious in shallow 

 water, especially on Tubularice. He remarks, that when touched, it discharges a fetid 

 colourless liquid, with the odour of Geranium Bobertianum, a circumstance we did not observe 

 in our specimen. 



Not one of the least attractions of Hermcea bifida is its crystalline transparency, which 

 adds much to the delicacy of its appearance. It is a very active animal, and when 

 in progression, expands and contracts itself with great rapidity. Its partiality to swimming 

 on the surface has been noticed by most of those who have met with it. 



Our specimen was received in October, and in the course of a day or two a single mass 

 of spawn was deposited in the vessel where it was kept, but not being fixed to any substance, 

 we cannot speak with certainty of its normal form. It was cylindrical and twisted in an 

 irregular manner, with the ova large, white, and arranged in transverse lines. 



Figs. 1, 2, 3. Herrruea bifida, various views. 



4. Two of the papillse much magnified. 



5. The tentacles highly magnified. 



6. Spawn. 



7. A portion of the spawn more highly magnified. 



