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 
separated 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 which sea 
they are found in considerable abundance. 
The term a^ovbvXog 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. 
