54 THE PROCEEDINGS OF THE LINNEA.N SOCIETY 



I may mention here that I saw a few days ago a fine specimen 

 of Vipsas fusca procured by Dr. J. C. Cox, from the Mudgee 

 district, a very unlikely place one would suppose for a snake of 

 its habits. 



I take this opportunity also of correcting a mistake of mine in 

 a previous paper. In page 221 of Vol. II. of our Proceedings, I 

 gave the name of Elapocephalus to a new genus of snakes from 

 Port Darwin. I find that Dr. Gunther had previously (Cat. Brit. 

 Mus., Snakes, App. 2, p. 276) used the same name for a genus of 

 South American Snakes of a very difierent family. I propose now 

 to substitute the generic name Elajpocranium for the Port Darwin 

 Snake. 



On the power of locomotion in the Tunicata. 

 By William Macleay, F.L.S. 



A few weeks ago I found the sandy beach at Elizabeth Bay, 

 strewn at low water, with a number of large Ascidian Mollusks. 

 In this there is nothing remarkable, the severe storm of the 2nd 

 of this month, having no doubt torn from their hold on the rocky 

 or sandy bed of the sea, these helpless masses. 



But I have observed with some astonishment that these masses 

 are, or seem to be, capable of a certain amount of locomotion. 



What I have observed is, that these large Ascidians do change 

 their positions most undoubtedly ; that in doing so they leave 

 upon the wet sand a distinct track in accordance with the weight 

 and size of the mass ; and that these movements are not in any 

 way attributable to winds or waves. I at first thought it possible 

 that the movements might be due to the agency of some of 

 the animals adhering to the outside of the mass, but I found 

 that the only organic attachments, excepting a few small shells, 

 were clusters of simple Ascidians, utterly incapable therefore 

 of combined action, and much two small for their individual 

 efibrts to produce any effect. 



