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On Perophora Listeri, an Ascidian found at Totland Bay, 



Isle of Wight. 



By Charles Rousselet, F.R.M.S. 



{Read Novemler 2Zrd, 1888.) 



Plate XXV. 



About the beginning of October, at the invitation of a friend, 

 I spent a few days at Totland Bay, in the Isle of Wight, and in 

 searching over the sea-weeds in the Bay at low tide, we found 

 some minute clusters of white jelly, which I did not remember 

 to have seen before. On placing a small piece of it under the 

 microscope at home I saw at once I had found a beautiful 

 Ascidian, whose name was soon ascertained to be Lister's 

 Perophora. The perfect transparency of the test enabled me to 

 study and understand the structure of this class of animals 

 much better than before by the mere reading of descriptions in 

 books. 



I brought several clusters with me to London, and although I 

 kept them in only a few ounces of sea-water, they remained 

 alive and in perfect condition for three weeks, and I exhibited 

 some at the Conversational Meeting of the Club on the 12th of 

 October. They also budded freely until a few days before our 

 meeting last month, when they suddenly died down, apparently 

 from the cold weather, which had then set in. I have mounted 

 a group in glycerine, which shows the structure very well, and 

 which is shown in the room under my microscope. 



I gave a branch of it to Mr. Waddington, in whose aquarium 

 they have revived again, so that I am enabled to exhibit some 

 living specimens also. Mine are not dead ; numerous buds 

 have been produced showing the pulsating heart, but they do 

 not attain maturity. 



As this pretty Ascidian affords such a good opportunity of 

 becoming acquainted with the structure of the class, I have 

 thought a few remarks on its anatomy would not be out of 



