SPONDYLUS. 61 



between them is exceedingly great. To the divi- 

 sion Pecten, particularly, the resemblance of the 

 longitudinal ribs and eared hinges is very remark- 

 able. Some species are, however, destitute of ears, 

 and of the exserted beak. 



These shells are attached to rocks at consider- 

 able depths in the ocean, from which they are se- 

 parated with the greatest difficulty. They are often 

 bored by Pholades and marine insects. 



The animals of the Spondyli are commonly eaten 

 on the coasts of the Mediterranean, in Vvhich sea 

 they are found in considerable abundance. 



The term o-TrovSyXo; is sometimes used for the 

 prickly head of an artichoke, though more gene- 

 rally for the vertebrae of the back-bone, to either 

 of which some likeness may be found in the Spon- 

 dylus. 



