SHELLS AND MOLLUSCOUS ANIMALS. 227 



it is the Netted whelk (Buccinum reticulatum), a 

 firm shell, much smaller than the preceding species, 

 though shaped much like them. Its surface is 

 marked with lines from the "base to the summit, 

 and again with lines around it, which crossing each 

 other, gave it its name. It is of a yellow colour, 

 often tinted with an ashy grey, and about an inch 

 long. Several of the different species of rock-shell, 

 or Murex, are common on our shores. The shells 

 are somewhat similar to the whelks in form, but 

 thicker and more wrinkled. Like the whelks, 

 they seem destined in an especial manner to pre- 

 vent the bivalve mollusks, and other shell-fish of 

 their own class, from becoming so abundant as to 

 fill our seas. They are all carnivorous, and con- 

 sume a large amount of prey, which they get at 

 by boring holes in the shells of the helpless 

 creatures destined for their food. Some of them, 

 as the Humble murex (Murex despectus}> common 

 on our shores, serve the fishermen for bait. 



Our figure represents a very pretty shell, not 



uncommon on some of our rocky shores. It is the 

 Pelican' s-foot strombus (Strombus pes-pelicanus) . 

 This shell, in its younger state, has not the 

 Q 2 



