62 



THE LIFE OF THE MOLLUSCA 



and Saxicava (Plate XIX., Fig. 14), but the majority 

 are more or less restricted, and are governed in their 

 geographical distribution by the physical characters 

 of the coastlines, by climate, and by currents. 



They are generally considered to be capable of 

 apportionment into nineteen " provinces," according 

 to the abundance of peculiar forms in each. Although 

 these provinces by no means strictly conform to the 

 parallels of latitude, they nevertheless can be con- 

 veniently grouped in climatic zones, beginning in 

 each case with those of the Atlantic Ocean, as 

 follows (see Map, facing p. 66) : 



1. Arctic. 

 Boreal. 

 Celtic. 

 Aleutian. 

 Atlantic. 

 Lusitanean. 

 Aralo-Caspian. 



8. Japonic. 



9. Californian. 

 fio. Caribbean. 



11. West African. 



12. Indo-Pacific, including the northern 

 shores of Australia. 



,13. Mexican. 



14. Patagonian. 



15. South African. 



16. Australian, including the southern 

 shores of Australia, with Tas- 

 mania, New Zealand, etc. 



Peruvian. 



Magellanic, with Kerguelen Island. 

 Antarctic, 



North J 

 Temperate 1 



Northern J 

 Subtropical ] 



Tropical 



Southern 

 Subtropical' 



U7- 



South | ig 



Temperate j 



19. 



