4 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 125 
iridescens Flint, Ochrotrichia spinossissima Flint, and Oecetis pratti 
Denning. These are distributed over the Greater and Lesser Antillean 
islands and may also be found on some of the adjacent mainland areas. 
The second pattern (map 2) is shown by Wormaldia planae Ross, 
Chimarra caribea, new species, Leptonema albovrens (Walker), 
Leucotrichia sarita Ross, and Oxyethira azteca (Mosely). This pattern 
shows a rather wide mainland distribution, generally from Mexico to 
Trinidad, and includes Grenada and, in the case of L. albovirens, 
St. Vincent also. The third pattern is shown by the remainder of the 
species that are endemic to one or more of the Lesser Antillean islands. 
Although the origin of the Lesser Antillean fauna is not absolutely 
clear, there does seem to be overwhelming evidence that there is a 
major difference in the composition of the Trichoptera fauna of the 
Greater and Lesser Antilles in spite of a few elements in common 
(those representatives of “pattern 1’’). The following genera or groups 
of species are all found on the Greater Antilles but are lacking on the 
Lesser: Atopsyche, Cariboptila, Campsiophora, Chimarra (Curgia), 
the Polycentropus nigriceps group, Antillopsyche, the Smicridea comma 
eroup, Hydropsyche, Macronema, Leptocella, Marilia, and the Phyllov- 
cus cubana group. The alternative of genera or species groups present 
on the Lesser Antilles but not on the Greater is also true: Protoptila, 
Polypleciropus, the Chimarra caribea group, Zumatrichia, Bredinia, 
the Smicridea nigripennis group, Atanatolica, Brachysetodes, and the 
Phylloicus lituratus group. 
There is only a little evidence concerning the actual source for the 
colonization of the Lesser Antilles. In the majority of cases the genera 
or species groups are found throughout South and Central America, 
but for unknown reasons they have managed to colonize only one group 
of islands or the other. In a few cases, however (the Chimarra caribea 
group, Atanatolica, Brachysetodes, and the Phylloicus lituratus group), 
all the related species are found in South America and southern 
Central America. In these cases at least, their ancestors probably 
came from northern South America. In fact, the second distribution 
pattern (Grenada and adjacent mainland) may well represent an 
incipient stage in the introduction of species into the Lesser Antilles 
from adjacent South America. 
Taxonomy.—The following keys to families were published in 
Flint (1964b) and were modified from Ross (1944). Designed for use 
with the Antillean fauna only, they use obvious external characters 
whenever possible. No specific determination should ever be con- 
sidered definite until the genitalia have been compared with, and found 
identical to, the figures for the species under consideration. The 
families Rhyacophilidae and Odontoceridae have not been taken on 
the Lesser Antilles, but they are included in the keys because of their 
presence on the Greater Antilles. 
