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anchors and plates of Synapta and the spicnles of Holothuria, would ba 

 remembered amongst many others. Mr. Stewart then directed attention 

 more particularly to the Echini, of which he gave a general description, 

 figuring the typical forms — the teeth, alimentary canal, nervous system, 

 &c. — upon the black board. Attention was then called to the structure and 

 arrangement of the spines, the five rows of sucking feet or ambulacral 

 discs, and the still more remarkable pedicellariaa. In addition to the draw- 

 ings made by Mr. Stewart in the course of his remarks, the subject was 

 further illustrated by a most interesting collection of mounted specimens of 

 hard structures of the Echinoderms, exhibited under nine microscopes in 

 the room. 



The President &aid he had listened to the address of Mr. Stewart with 

 the utmost interest, and had felt it to be most instructive. He was in the 

 Isle of Man some time ago, and went in a boat out to the island called the 

 Calf of Man. The weather was very calm, and he found upon the rocks a 

 large number of Echini within reach of his arm. They were upon a kind of 

 shelf, and he particularly noticed that each one had a hollow place scooped 

 out under it, which seemed, without doubt, as if it had been made by the 

 creature itself. The land about that part is mostly of volcanic origin, and 

 the rocks are exceedingly hard, so that it would seem difficult for these 

 creatures to excavate the hollows themselves ; but he should like to ask Mr. 

 Stewart if it were possible for them to do this, and also by what means it 

 was done. 



Mr. Hainworth enquired how Mr. Stewart preserved Ecliini, and also 

 what was the best way in which to mount them, so as to exhibit them to 

 the best effect. 



Mr. T. C. White said he had a specimen of Alcyonium, digitatum (exhibited 

 in the room), in the mouth of which he found some Echinus spines, and he 

 had often wondered whether the Alcyonium preyed upon the Echinus, or 

 vice versa. The spines were found in the mouths of these Polyps in several 

 other instances also. 



Mr. Charles Stewart said, in answer to the President's question, that the 

 subject was one which had frequently received attention, for, in the case of 

 the common Echinus fEchinus lividusj, it was invariably found that these 

 depressions existed, and the way in which they were supposed to be formed 

 was by the constant sucking action of the ambulacral tubes. It had been 

 supposed by some, that the spines had something to do with the formation 

 of these hollows, but this was not at all borne out by examination, as not 

 even the smallest spines showed any appearance of being worn away. With 

 regard to preparation, the smaller star fish presented very little difficulty, 

 as they had no tendency to throw off their arms as the others did. The 

 best way was to put them upon a piece of glass, and spread them out with 

 a needle, then allow a little fresh water to run up to them, though not 

 enough to let them move about, this speedily killed them, and they could 

 then be turned over and spread out with a needle. If it was desired to 

 mount them transparently, they should be dropped into spirit, and then into 

 oil of cloves and balsam in the usual way. He thought that, in the cases 



