CHAPTER III. 



SHELLS AND .MOLLUSCOUS ANIMALS. 



" Even as the rainbow-tinted shell which lies 

 Miles deep at bottom of the sea, hath all 

 Colours of skies, and flowers, and gems, and plumes." 



IT is an interesting question, and one which 

 yet is not fully answered, how far living creatures 

 can exist below the surface of the deep. The 

 wondrous architects of the coral reef cease to live 

 at 100 feet below that surface, and so vast a 

 number of shell-fish and crustaceous animals, of 

 corallines and other zoophytes, dwell within a few 

 yards of it, that the statement seems probable, 

 that below the depth of a few hundred feet life 

 ceases in the ocean, from the want of air and light, 

 and from the pressure of the waters. 



Yet the words of the poet are true enough. 

 Miles deep at bottom of the sea, must lie the 

 structures of myriads of once living animals ; and 

 shells of graceful form and glowing colours add to 

 the constantly accumulating substance at the base 

 of the ocean. Many are strewed upon our sandy 

 shores, and so beautiful are they, that we wish, in 

 our summer rambles, that the waves would bring 

 them up to us in greater numbers, or that we 

 could look down on a clear day into those recesses 

 where 



" Buoyant shells, 



On stonnless voyages, in fleets and single, 

 Wherry their tiny mariners." 



