82 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



leaving the posterior motionless. Fig. 3 represents the 

 condition of things at noon, and immediately afterwards 

 the intestine was detached at its junction with the cloaca 

 in the posterior end p, and during the next two or three 

 days was trailed about by the anterior portion a. Even- 

 tually it decomposed and disappeared in fragments. At 

 no time during the process of division were the tentacles 

 visible. On July 21st I noticed that the posterior end had 

 developed a new mouth and a circlet of minute tentacles. 

 The latter slowly increased in size, but were seldom pro- 

 truded except after aeration of the water. 



On July 26th another specimen repeated the above 

 process of spontaneous division in much the same way 

 and in about the same time, the only variation being that 

 the anterior portion took possession of the whole of the 

 intestine soon after its detachment from the cloaca. This 

 specimen had previously discharged a large number of ova, 

 assisting their dispersion by active play of the tentacles. 

 The process of division was again repeated at the middle 

 of August by the third specimen, and a fortnight later the 

 posterior end of this divided, so that at the end of the 

 month I had seven specimens. Cucumaria planci appears 

 to be a hardy species, and well adapted for marine aquaria. 



Explanation of Plate I. 



Figs. 1 and 3, show stages in the fission of Cucumaria 

 inland, natural size. 



Fig. 2, shows rupture of middle of body, enlarged. 



