THE SHORES OF BRITAIN. 57 



it were, to the form of the enclosed animal, thus in- 

 creasing the size and commodiousness of the dwell- 

 ing, and precluding the necessity of quitting the tene- 

 ment. ]\Ir. Gray remarks on this : — " One can under- 

 stand that the Crab may have the instinct to searcli 

 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 {H. infundibulifonnis). 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 astonish- 

 ing 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 centre of the upper 

 surface is depressed, and there is evidently an aper- 

 ture which has been closed. "WHien 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 outer rim protrude a multitude 



