100 INTRODUCTION. 
There is another branch of this subject which de- 
mands attention, as connected with the introduction of 
foreign species, and that is, the distribution in the neigh- 
boring countries and islands, of those species which are 
usually admitted to be indigenous to the United States. 
In the dearth of zoological information concerning that 
part of North America south of the United States, we 
find but few facts recorded which illustrate the subject, 
and hence we can present nothing of much interest. 
We have reduced the observations into the form of a 
table, which will show at one view all that we have been 
able to gather. We include in it Bulimus zebra ami 
B. fasciatus, because, although we believe, from their 
appearance in our territory only on the southern point 
of the peninsula of Florida and on the small islands 
closely adjacent, that they were accidentally introduced 
from the neighboring island of Cuba, others may not be 
of the same opinion, and it may be interesting to ascer- 
tain their range as well as that of the other species. In 
the British provinces at the north of the United States. 
the observations are still fewer in number, and we are 
acquainted with only a single local list (and that a very 
meagre and incomplete one,) 1 of the land-mollusks oc- 
curring in any part of the British North American pos- 
sessions. We know, however, from authentic informa- 
tion, that many of the species indigenous to our fourth 
zoological section, are also common to the peninsula of 
1 Mrs. Sheppard's, in the Transactions of the Literary and Historical 
IV of Quebec, Vol. i. p. 88. 1S29. 
