COMMON EGG-UKCHIN. 297 



orifice of the shell, while its base is connected with 

 several bony levers by means of numerous muscles 

 provided for the movements of the whole. When 

 the five jaws are fixed together in their natural posi- 

 tion, they form a five-sided conical mass, aptly 

 enough compared by Aristotle to a lantern, and not 

 unfrequently described by modern writers under the 

 name of " the lantern of Aristotle/' The whole of 

 this complicated machinery is suspended by muscles 

 from a frame-work fixed in the interior of the shell, 

 and may often be picked up upon the "beach, or 

 still better exposed in situ in a dead Echinus, by 

 those who would examine closely this wonderful 

 piece of mechanism/ l 



I have made two careful drawings of the jaws 

 and teeth of the Echinus. No. 1 represents, as it 

 were, the ' elevation' of the pentagonal pyramid 

 above described, while No. 2 constitutes the 'plan' 

 of the same object. 



The Echinus sphcera, or common Egg-Urchin, 

 may often be seen forming a curious ornament 

 in the drawing-rooms of the "West End," and 

 also in the dwellings of the poorer classes, who, 

 according to some authors, boil it like eggs, and 

 so eat it. Hence its popular title. Among the 

 ancients the Echinidse were accounted a favourite 

 dish. * They were dressed with vinegar, honied 



1 The 'Aquarian Naturalist,' p. 224. 



