1941 ] 
West Indian Carabidse VI 
15 
tude of about 4,500 ft., which is about as high as there are 
brooks in the Jamaican mountains. Some of the same 
species occur also along lowland streams; others are con- 
fined to the banks of the mountain torrents. Two or more 
winged Colpodes of the bromeUarum group occur on the 
mountain slopes, and probably live between the leaf bases 
of broad-leaved, pineapple-like bromeliads, in trees. And 
other winged Carabidse, some of them lowland species but 
others perhaps peculiar, are to be expected in proper habi- 
tats on the lower and middle mountain slopes. 
With increasing altitude, a few flightless Carabidse, with 
reduced or vestigial wings, begin to appear among the 
winged ones, and from the 5,000 ft. level to the highest 
summit (7,388 ft.) flightless species predominate. Ten 
species of Carabidse have been found at or above 5,000 ft. 
in the Jamaican mountains. Only 2 of the these species, 
both perhaps arboreal, have fully developed wings. The 
other 8 species have reduced or vestigial wings, and are 
flightless. They live chiefly or entirely on the ground in 
damp cloudforest. 
Of course, there is still much to be learned about the de- 
tails of distribution of Carabidse in Jamaica, but the main 
pattern is already very clear. In the lowlands, there is a 
rather numerous and diverse fauna of Carabidse, all winged. 
On the middle slopes of the mountains, there is a smaller, 
mixed, transition fauna. And at highest altitudes there is 
a small fauna which is predominantly flightless. 
Similar conditions are found throughout the Greater 
Antilles ( cf . Darlington, Memorias de la Sociedad Cubana 
de Historia Natural 13, 1939, pp. 79-80). Throughout the 
lowlands of each island are found numerous and diverse 
Carabidse, all or nearly all of which are winged. But wher- 
ever mountains rise above 5,000 ft. a few endemic, alti- 
coline, flightless species occur, most of them apparently 
derived in situ, independently on the different mountain 
tops, from winged ancestors. 
This is not an accidental phenomenon. It appears to be 
the result of the action of powerful environmental forces. 
But it is difficult to say just what the forces are, for they 
are complex as well as powerful. I shall try to deal with 
them in another paper. 
