THE SHORES OF BRITAIN. 69 
the necessity of quitting the tenement. Mr. Gray 
remarks on this:—“One can understand that the 
Crab may have the instinct to search for shells on 
which the coral has begun to grow; but this will 
scarcely explain why we never find the coral except 
on shells in which Hermit Crabs have taken up their 
residence.” 
One of the most pleasing forms that are presented 
by the Sponges, which are exceedingly various, is 
that of a cup with a dilated foot; it is about as large 
as a tea-cup, but is more funnel-shaped, whence its 
name (ZH. infundibuliformis). A similar species from 
the Indian seas, commonly called Neptune’s Cup, 
though much larger, is inferior to our little goblet in 
neatness of appearance and sponginess of texture. 
Our shores abound with examples of those asto- 
nishing forms of animal life, the Polypes, both simple 
and aggregated. The former under the names of 
Animal-flowers, and Sea-anemones, have attracted 
general admiration from their intrinsic beauty, and 
from their very close resemblance to composite 
flowers. When out of water, or reposing, they 
usually take a semi-globular shape, adhering by a 
broad base to the rocks, but some are somewhat 
lengthened and cylindrical. The céntre of the upper 
surface is depressed, and there is evidently an aper- 
ture which has been closed. When seeking for prey 
this orifice opens, by its edges turning inside out, as 
it were, and dilates, until it is as wide as the base; 
while from within the lip, or outer rim, protrude a 
multitude of fleshy rays, called tentacula, arranged 
in three or four rows extending all round. In the 
