144 SEA-SHORE LIFE 
The shell grows to be about three inches long, and is marked 
with revolving ridges and transverse furrows, and its outer surface 
is covered with a velvety brown skin. It is carniverous and readily 
feeds upon dead animals. 
During the summer its egg cocoons are often found attached 
to rocks below low tide level. They consist of a mass of rounded 

Fig. 103; Rock Snails (Purpura lapillus) devouring barnacles upon a rock at Annisquam, Mass. 
capsules, yellow in color, all joined at their bases into a hemispher- 
ical mass. They are popularly and aptly termed “‘seacorn.” Each 
capsule contains a number of eggs, but only a few develop, the 
more vigorous young devouring the weaker before hatching. 
In England this snail is sold in the markets, but with us it is 
neglected. The lip of the shell is very apt to be broken in large 
specimens. 
The Rock Snail, (Purpura lapillus, Fig. 105). This snail 
