1869.] and Membranipora Bengalensis. 49 



periphery of the base, till it wholly disappears towards the centre. 

 I have never seen any acontia issuing from the tentacles, or any part 

 of the disc ; as a rule they are emitted only from the sides of the 

 column, but when the animal has been removed from the place of 

 its attachment, I have seen them as already stated, to be emitted from 

 the base near its periphery. 



Grosse says that each cinclis is not assigned to a special acontium, 

 but that at the contraction of the animal, a quantity of water is thrown 

 out, carrying the acontia with it, and issuing them through any cinclis 

 which happens to lie nearest. This appears in general to be correct ; 

 but at the same time it can, I believe, hardly be questioned that 

 some muscular power is connected with the issue of the acontia, and 

 perhaps the motion of the water only supports the former principal 

 action, and directs the acontium towards a cinclis. It would be, for 

 instance, impossible to understand why in the fresh and healthy 

 animal, nearly all acontia issue at the collar ; and besides that some 

 of them are under circumstances issued with great force in a contracted 

 state of the animal, where extremely little water is given out. More- 

 over it is very probable that the same muscular power which retracts 

 the acontia, after they were ejected, is also in operation at the act of 

 their emission. 



Regarding the digestive system of which I have previously treat- 

 ed, I must here record a very interesting observation, inasmuch 

 as it supports the suggestions previously made. I fed a large 

 specimen with a small Crustacean,-after it had been slightly press- 

 ed, so as to reduce its active motions, and prevent its escaping 

 from the mouth of the animal. The Sagartia kept the Crustacean 

 for about five minutes between the lips, and then by almost insensibly 

 slow movements of the labial muscles gradually swallowed it down. 

 When this had been done, it remained in a half contracted position 

 for more than an hour. During this whole time the craspeda were 

 seen much more actively moving about, than either before or after 

 that. The Crustacean was actually so thoroughly enveloped in the 

 not of the craspeda, that I could not trace its form ; even the next day 

 the craspeda were seen more approximate and arranged round the 

 central space, than they were on former occasions. This observa- 

 tion appears to be in favour of my previous statement, that the 



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