PERILS OF THE OYSTER. 231 



it occupies the centre of a soft space invested with a thick 

 resisting membrane ; it opens and shuts incessantly, show- 

 ing five sharp teeth projecting from the surface, the edges 

 meeting at a point, supported and protected by a very 

 complicated framework, which has received the name of 



Aristotle's Lantern To this 



formidable mouth is attached an oesophagus or gullet, and 

 an intestine which extends along the interior walls of the 

 corona, describing the circumference of its principal con- 

 tour. The food of the Echinidoe is still imperfectly 

 known ; nevertheless, from the presence of shells, frag- 

 ments of coral, crustaceans, and even other Echinoder- 

 mata in their intestinal tube, it is to be inferred that a cer- 

 tain number of them at least are carnivores, or flesh-eaters, 

 while others are supposed on the same evidence to be 

 vegetarians." (_/") 



That the Echini are to be regarded as vermin, in the 

 oyster-pares, has been proved by the following evidence. 

 In the month of May of a certain year, a sudden inroad of 

 these sea-urchins was discovered in the Paglesham fishery, 

 and by the month of August of that year they had eaten 

 an enormous quantity of oyster the size of a split pea. 

 Frank Buckland noticed several of these creatures on the 

 oyster-beds in Kilkerran Day, near Ballynahinch, Galway, 

 and naively remarks that "they were not there for nothing." 



Another supposed enemy of the oyster is the crab, 

 which is too well known to need description here. This 

 animal is certainly grotesque enough and most amusing in 

 its habits ; it has been supposed to be an oyster enemy by 



(/) "The Ocean World." 



For further information relative to this interesting creature see the 

 above-named work. 



