THE ECONOMIC MOLLUSCA OF ACADIA. 
17 
an absolute right to the products of their labor and protection 
from trespassers, but even, if necessary, positive encouragement 
in the way of bounties, until Oyster-culture shall become an 
established industry of the Dominion. Canada does not now 
produce more than a fraction of the Oysters she uses; it is 
soon to become a question of deriving the greater part of her 
supply frem cultivated beds in the United States or from 
cultivated beds in Canada, for the natural beds of the United 
States are rapidly becoming exhausted, and attention is being 
directed towards culture. 
Something should be said here as to the distribution of 
Molluscs in our waters. It will be noticed by those who read 
the following pages, that many forms are spoken of which 
occur in the Gulf of St. Lawrence and not elsewhere north of 
Cape Cod; others occur in the Bay of JFundy, the distribution 
of which is circumpolar or arctic. These are two among very 
many facts which indicate a curious distribution of animal 
life in Acadian waters. In the southern part of the Gulf, all 
along the North Shore of New Brunswick and Nova Scotia 
and all around the coast of Prince Edward Island and Cape 
Breton, occur animals of species identical with those living to 
the south of Cape Cod, and in most cases they do not occur 
in numbers between those localities. The Oyster, Quahog, 
Drill ( Urosalpinx ), Plicated Mussel, are all examples of this, 
and many others might be mentioned which do not fall with- 
in the limits of this paper. In the Bay of Fundv and on the 
coast of Nova Scotia, south of Chebucto Bay, on the other 
hand, the forms are decidely northern, the uniformly cold 
water of that region not allowing of the development of the 
young of such southern forms as can thrive in the Gulf. In 
the latter, the shallow waters, little disturbed by tides, can 
become very warm during the summer, and favorable con- 
ditions thus being provided for the young, the adults survive 
them in spite of the cold of winter. For the origin of this 
condition of affairs we must look to geological causes, the 
discussion of which is not in place here. The substance of it 
is, that in times recent geologically (certainly post-glacial), an 
