NEDIBEANCHIATE MOLLUSCA FEOM THE EASTEEN SEAS. 125 



expeditions. I brought them home, and placed them in water till the next day, intending 

 by daylight to draw and describe them. But on visiting them in the morning, I found 

 that they had performed a spontaneous amputation of the mantle close to the body all 

 round. It was done as cleanly as if by a pair of scissors. A large Pyrula in the same 

 vessel was at first credited with this act ; but other specimens having been placed separate 

 in clean water, not being able to attend to them immediately, I found on visiting them 

 next day that they also had amputated their mantles and were destroyed. It appeared 

 to be a suicidal act, or " happy despatch," similar to the self-evisceration of Holothuriae 

 and breaking up of Comatula3 under the influence of the gradual fouling of the water. 



These delicate and beautifully tinted animals are so entirely altered as to their form 

 and colour by spirit, that I can scarcely understand how new species can be satisfactorily 

 described from spirit-specimens. Alcohol bleaches their colours, and contracts to shape- 

 lessness the most beautiful elements of their form, the mantle, but more especially the 

 tentacles and branchiae, so that they bear no resemblance whatever to the living animal. 

 It keeps them, however, fit for dissection. The spicula, odontophores, buccal collars, and 

 other important classificatory characters are thus well preserved. Glycerine, while it keeps 

 for a considerable time their colour and form, renders them soft and comparatively useless 

 for dissection. The only way to retain a correct idea of their living character is to make 

 careful drawings of them in their active condition ; and whatever value the present 

 illustrations may have is founded upon this circumstance, for they are faithful to the life. 



With regard to the two species of the Polybranchiate family of Phyllidiadae (the only 

 ones I met with, and found side by side in a rock-pool on the coast of Borneo), I have 

 consulted Bergh's elaborate paper in the ' Naturhistorisk Tidsskrift ' for 1868-69, and 

 also that in Heft 10 of Semper's ' Beisen im Archipel der Philippinen,' in both of which 

 papers species are described and figured ; but although there is some resemblance, I 

 cannot assure myself that the Phyllidiella pustulosa figured by him is the same as my 

 Phyllidia spcctabilis. 



Nothing more need be added in these introductory remarks concerning the species to 

 be described in this paper. As to the works to which I have been indebted in the inves- 

 tigation, I would chiefly mention two, viz. the well-known and invaluable ' Monograph ' 

 of Messrs. Alder and Hancock, published by the Bay Society, which has been to me as 

 a companion ever since its publication ; and, secondly, the " Bevision of the Anthobran- 

 chiate Nudi branchiate Mollusca," by Mr. P. S. Abraham, in the Proc. Zool. Soc. 1877 : 

 other memoirs are referred to in the text. 





List of the Genera and Species enumerated in the present Paper. 



Albania formosa. 

 Triopa Principis-Wallise. 

 Trevclyana felis. 

 Doridopsis arboresmis. 

 — rubra. 

 Phyllidia spectabilis. 

 Fryeria variabilis. 

 Scylhea pelagica. 

 Bornella nianuorata. 



Doris pecten. 



cresceutica. 



Cbromodoris iris. 



Bullockii. 



aurco-purpurea. 



tumulifcra. 



tennis. 



funcrea. 



Alderi. 



17* 



