602 



THE MARBLED CHITON AND THE SNAIL. 



Chiton Magnif- 



ICUS. 



have a somewhat saddle-like shape. A similar arrangement may be 

 observed in the lower abdominal plates of many beetles. Each of 

 these plates is fixed to the mantle by certain rounded processes from 

 their front edge, and when the plates are examined separately the 

 processes will be plainly seen, white and pearly as 

 the interior of the shell. 



The Chitons are able to roll themselves up in a 

 partial kind of manner, and present a curious re- 

 semblance to the well-known armadillo or pill- 

 woodlouse. 



The Marbled Chiton is a rather prettily-colored 

 shell, its exterior being rusty red mixed with brown 

 and yellow and edged with brown. 



Passing from the sea to the land, we come to those 

 Gasteropods which breatlie atmospheric air, and are 

 furnished with respiratory organs suited to the ele- 

 ment in which they live. 

 The first family is that of the Snails, or Helicidse, containing a vast 

 number of species. Most of the Snails have a shell large enough to 

 permit the animal to withdraw itself wholly into the protecting domicile. 

 The genus Helix, which is universally accepted as the type of .this 

 family, is of enormous extent, both in numbers and in range of locality, 

 containing more tlian fourteen hundred species and spread over nearly 

 the whole earth. 



Our present example is the common Snail, which is even now 

 largely consumed in many 

 parts of the world, and is 

 regularly fed and fattened 

 for that purpose. 



It is thought a delicacy 

 by those who are sufficiently 

 strong-minded to eat it, and 

 it is quite common to see, 

 even in Paris, the poorer 

 orders dressing their dinner 

 of snails on an iron plate 

 heated over burning char- 

 coal. 



An allied species, the 

 Edible Snail {Helix po- 

 matla), was introduced into England by the Romans, and still exists 

 in many places. 



Toward the end of autumn the Snail ceases to feed, withdraws itself 

 to some sheltered spot, mostly under grass, moss, or dried leaves, and 



The Common Snail {Helix aspersa). 



