HALF AN HOUR WITH SHELL-FISH. 



201 



Fig. 108. 



Cyyrea Europea. 

 Fig. 109. 



when protruded, are as pleasing, or more so, as the 

 shell itself. 



The "Purple-shell" (Purpura lapillus, Fig. 109) 

 is nearly as abundant in every rock- 

 pool as the periwinkle. Along the 

 southern coasts it is found of a 

 white colour, with dark brown bands 

 running up the centre of every 

 whorl. It is a very stout, strong 

 shell, and alters in its colour with 

 age. In the northern seas, however, 

 it would seem as if the pure white- 

 grounded and brown-banded variety 

 was much scarcer than farther 

 south. The older specimens have 

 the inner surface of the lip tinged 

 with a rich, rosy purple. It takes 

 its name from its power of exuding 

 a purple dye, and it is believed to 

 be one of the species that furnished 

 the ancient Tyrian purple. The egg-cases of this 

 shell may be found in abundance under ledges of 

 rock, where, as Mr. Gosse remarks, they resemble 

 "Nine-pins in shape, set on their ends in close 

 contact with each other, and varying in numbers 

 from three or four to a hundred or upwards in a 

 group. Some of them are tinged with purple at 

 the tips, and while sometimes you find them closed, 

 and full of a yellow, creamy substance, at others 

 they are open at the top and empty." The tongue 



Purpura lapillus. 



