184 On British Zoophytes, with descriptions ofnew Species. 



from its base. As the latter increased, the polype exhibited the 

 appearance which precedes absorption ; the arms became con- 

 tracted and rigid, and at length almost disappeared. At the 

 same time a dense fluid filled the interior, in which an extraor- 

 dinary ferment was perceptible. Numbers of spherical bodies, 

 most of them opake, as if laden with matter, might be seen 

 bustling to and fro, and hurrying down the central channel, 

 which communicated with the new offshoots, into which they 

 penetrated. The process of absorption proceeded until the ori- 

 ginal polype-head had altogether vanished, its substance having 

 gone to buUd up the new stem, which had now attained a con- 

 siderable length. The destruction of the specimen put an end 

 to my observations, but there can be no doubt that a polype 

 would soon have been produced at the extremity of the shoot. 



A polype, then, artificially detached from the Cordylophora is 

 capable of originating a new organism. It may be hkened to a 

 precocious planula. It is in fact a bud which has been developed 

 into the polype form while in connection with the parent struc- 

 ture, while the planula is a bud which has become free, before 

 assuming that form. 



MiMOSELLA GRACILIS. 



Since I first described this beautiful production in the 'An- 

 nals,' I have had the satisfaction of dredging it in some abun- 

 dance in Torbay. It occurred here, as in Salcombe Bay, where 

 it was originally obtained, on rocky ground at a short di- 

 stance from the shore, and was always, I think, parasitical on 

 the same weed. Mr. W. Templer has also procured a specimen 

 which was cast on the Plymouth Breakwater after a gale of 

 wind. The species therefore would seem to be pretty generally 

 distributed along the western coast. 



A renewed examination of the Mimosella in its living state 

 enables me to add a few words on its peculiar habits. 



The movement of the cells always accompanies either the 

 retraction or expansion of the polype. When the polypes on both 

 sides of a pinna are withdrawn, the cells are all folded together, 

 like the leaflets of the Mimosa when touched. But each one of 

 them when about to issue throws back its cell, and then imme- 

 diately darts forth. When it retreats, the cell returns to its 

 former position. 



Great numbers of pinnae were met with covered with budding 

 polype-cells in various stages of development. They appear at 

 first as small, roundish excrescences on the branch. 



EUCRATEA CHELATA. 



One of the leading characters of the family of Eua-atiadee, as 

 constituted by Dr. Johnston, is the absence of " external ovarian 



