To identify shells of Venezuela I think I would start with Seashells of
Brazil by E. C. Rios.  The old Caribbean Seashells by Warmke and Abbott,
though dated, would probably be useful too. Abbott's American Seashells
includes a lot of lower Caribbean species.  And the new A Thousand Species
from Abaco, Bamahas, by Colin Redfern would also be useful. The Bahamas are
a long way from Venezuela, and many species are not found in both places,
but many others range throughout the Caribbean.

Paul M.