MANUAL OF NATURAL HISTORY. 115 



containing species peculiar to itself, Jamaica being 

 particularly rich in Gyclostomata, Helicince, and Cy- 

 lindrellce. South America is the grand emporium 

 of the Bulimi and Ghilince ; while the great rivers 

 of North America are extremely prolific in Unio 

 and Anodonta; and the West coast is remarkable 

 for its numerous examples of Chiton, Calyptra and 

 Fissurella. The islands of the Pacific Ocean also 

 exhibit several peculiarities in their molluscous 

 fauna ; the Struthiolaria and Amphibola are from 

 New Zealand ; the Trigonia, Chamostrea, and M y- 

 ochama, are from New Holland ; the Partula is 

 from the Society and Sandwich islands ; while the 

 Orthostylus and kindred forms people the wooded 

 parts of the Philippines ; and the Nanina is from 

 Borneo and Java, which also furnish us with nume- 

 rous Auriculce. The great Island of Madagascar 

 and the other islands in the Indian Ocean, also 

 yield their peculiar species of mollusks, both terres- 

 trial and marine. 



II. SUB-KINGDOM OF MOLLUSKS. Mollusca. 



Animal invertebrate, without jointed limbs ; body 

 soft, furnished with a mantle, which usually secretes 

 a calcareous envelope or shell; heart bilocular; ner- 

 vous system forming a transverse series of medullary 

 masses, or ganglia arranged around the gullet. 



CEPHALOPODS. 



The Cephalopods, comprising the Cuttle-fishes, 

 the Squids, the Argonauts, and the Nautili, are by 



