LIMPETS. 



95 



The Pacific seacoast abounds in Limpets. They 

 are harmless, vegetable-eating mollusks, which cling 

 to the rocks, and are protected by shells shaped like 

 inverted saucers. Many of them seem to have per- 

 manent habitations, and though they make frequent 

 short excursions, they come back to roost on the old 

 spot, which becomes worn and scarred by their con- 

 stant presence. The anatomy of these animals is 

 similar to that of other mollusks. There is a mantle 

 lining the free parts of the shell, a broad, muscular 

 foot, a head with a pair of eyes and feelers, a mouth 

 fitted with a crescent-like jaw, and a long tongue set 

 with flinty hooks. There are gills for the purification 

 of the blood, a liver, a heart, and other organs of 

 digestion, circulation and secretion. A few species 

 have an opening in the top of the shell, which serves 

 the same purpose as the holes of the Haliotis. 



By far the largest of the Key-hole Limpets, as they 

 are called, is named Lucapi'jia cre7ttclata^ Sby. , Lu-ka- 



Fig. 79. 



pi'-na cren-u-la'-ta. A small figure of the shell is 

 shown in Fig. 79. Though this shell is often some 

 four inches long, the animal is much larger, and 

 somewhat resembles a brick, both in shape and size. 



