CHAP. XIV.] 
THE NEOTROPICAL REGION. 
77 
It is probable that the three chief islands, Cuba, Jamaica and 
Hayti, are nearly equally rich in land-shells; but the last is 
very much less known, and therefore, perhaps, appears to be 
much poorer. Cuba has rather more species than Jamaica; 
but while the former has only 1 peculiar genus (. Diplopoma ), 
the latter has 3 (Geomelania, Chittya, and Jamaicea), as well as 
two others only represented in the other islands by single 
species. From Hayti, only about one-third as many species are 
known as from the two former islands. It has no peculiar 
genera, but it has some forms in common with Cuba and others 
with Jamaica, which show that those islands have more connec- 
tion with it, than with each other ; just as we found to be the 
case in birds. Portorico and the Virgin islands have still fewer 
species than Hayti; and, as many of the genera common to the 
other three islands are wanting, there is, no doubt, here a real 
deficiency. In the islands farther south (Barbuda to Martinique) 
more Antillean genera disappear or become very rare, while 
some continental forms take their place. The islands from St. 
Lucia to Trinidad have a still more continental character ; the 
genus Bulimus , so largely developed on the continent, only 
reaching St. Lucia. The Bahamas contain about 80 species of 
land-shells, of which 25 are Antillean, the rest peculiar ; all the 
genera being Antillean. The affinity is chiefly with Hayti and 
Cuba, but closest with the latter island. 
In the West Indian islands as a whole, there are 11 peculiar 
genera; 9 operculate ( Geomelania , Chittya , Jamaicea , Licina, 
Choanopoma, Ctenopoma, Diplopoma, Stoastoma , Luciddla) ; and 
2 inoperculate ( Sagda and Stenopus ), besides Cyclostomus, 
which belongs to the Old World and is not found on the 
American continent. Mr. Bland considers, that many of the 
Antillean land-shells exhibit decided African and Asiatic, rather 
than South American affinities. A species of the Asiatic genus 
Diplommatina has been found in Trinidad, and an Indian 
species of Ennea occurs in Grenada and St. Thomas ; a clear 
indication that land-shells are liable to be accidentally imported, 
and to become established in the less productive islands. 
Although these islands are so wonderfully rich even now, 
