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 
North | ? ae 
3. Celtic. 
ea 4. Aleutian. 
( 5. Atlantic. 
6. Lusitanean. 
Northern J : 
: 7. Aralo-Caspian. 
Subtropical 8, Japouie, 
g. Californian. 
(to. Caribbean. 
11. West African. 
Tropical 412. Indo-Pacific, including the northern 
shores of Australia. 
13. Mexican. 
14. Patagonian. _ 
15. South African. 
Southern }16. Australian, including the southern 
Subtropical shores of Australia, with Tas- 
mania, New Zealand, etc. 
(17. Peruvian. 
South 118, Magellanic, with 
toe - Magellanic, with Kerguelen Island. 
1g. Antarctic. 
