42 THE HAUNTS OF LIFE 



Sponges, sea-anemones, acorn-shells are fixed 

 animals, and they depend for food on what 

 they can sweep in from the water, or on what 

 they can catch as it passes by. But we must 

 take some examples of more vigorous ways of 

 feeding on the part of animals which roam 

 about from place to place. The periwinkles, 

 such as Littorina littorea, which is one of the 

 poor man's "oysters," creep about browsing 

 on delicate seaweeds, and it may be noticed 

 that those sea-snails which have an unbroken 

 outline to the mouth of their shell are vege- 

 tarian, while those with a deeply in-cut notch 

 at the mouth of the shell (a groove for the pro- 

 trusion of a breathing tube) are carnivorous. 

 The vegetarian Gasteropods are palatable; the 

 carnivorous ones hardly ever. So if we are 

 wrecked on a desert island we must begin our 

 seashore meals with those sea-snails that have 

 no notch at the mouth of their shell. 



Very different from the periwinkles are the 

 whelks and "buckies" which roam about in 

 search of animal food. We often find on the 

 sandy beach one of the valves of a bivalve 

 shell, e.g. Venus Gallina, with a hole neatly 

 bored through it, as neatly as if it had been 

 made by a gimlet. In many cases this hole 



