CLASS II. GASTEROPODA: ORDER 2. li R ANOIII FER A. 



515 





CULATED Sek-Eah, Ilaliotis tuherculata, grows to a large size in intertropical seas; it is also 

 common on the coasts of the islands of Jersey and Guernsey, where it is used for food, being 

 esteemed very palatable. It is well beaten to make it tender, before being cooked. The shell is 

 much used for inlaying, and other ornamental purposes. 



THE nSSURELLIDJi;. 



These are nearly related to the preceding; the shell resembles that of the limpet. The species 



are numerous and widely distributed. They inhabit rocky beds and reefs at various depths. 



The Greek Fissurella, F. Orceca, is found in the Mediterranean and the 



Indian Ocean. There are one hundred and twenty other known species 



of this genus. 



THE PATELLID^. 



This includes the Limpets, Avhich have a conical shell, the interior of 

 whicli is entirely occupied by the animal. They are spread over every 

 latitude, except in the Arctic regions. Millions are taken every year in 

 Great Britain for fish-bait, and immense numbers on the coasts of Ireland 

 for food. They are found principally on rocky coasts, attached to stones and shells, at a depth 

 rauginf from the surface of the water to thirty fathoms. They feed on sea-weed, in the masti- 

 cation of which their rasp-like tongues are very efficient. They attach them- 

 selves so firmly to rocks and shells, by creating a vacuum on the under sur- 

 face, that they can be detached with difficulty. It is even said that they have 

 the power of dissolving and absorbing the substance to which they are affixed, 

 PATELLA PECTONATA. ^^ ^^ oftcH to crcatc a deep excavation beneath them. There are many species, 

 varying in form and size, the largest being found on tropical shores. The Patella pectonata is 

 found in the Mediterranean. A very small species, the P. Candida, is found in our waters. On 

 the western coast of South America, there is a species a foot in diameter, and the sliell is used 

 by the inhabitants for a basin. Forbes tells us that each limpet has nineteen hundred and 

 twenty teeth. 



THE GREEK FISSURELLA. 



THE CHITON CHILENSIS. 



THE CHITON SPINOSUS. 



THE CHITONID^. 



In the Chitons the shell is composed of eight calcareous plates, overlapping one another at the 

 edges, and united by a strong leathery mantle, wliich forms a border all round the shell. In 

 some species the mantle is fringed with hair, and in others with bristles or spines. The kinds 

 are numerous, and are found on nearly all rocky shores, adhering to stones and other submarine 

 bodies, like the limpets ; a few have the habit of creeping in the sand. More than two hun- 

 dred species are known. The Chiton Chilensis has a smooth border ; it is found in crevices of 

 rocks and under stones, near Valparaiso. The Chiton spinosus is bordered by long, black, acule- 

 ated spines; found in the South Seas; length three inches. Several small species are conrnion 

 on our coasts. 



