A REVISION OF THE LAND SNAIL HELICINA ORBICULATA (GASTROPODA: PROSOBRANCHIA) FROM THE SOUTHERN UNITED STATES

摘要

Frozen tissue samples from living specimens of two subspecies of the land snail Helicina orbiculata (Say) from Texas and Florida were subjected to standard horizonal starch gel electrophoretic analyses in the laboratory. This included sympatric populations of both subspecies from two collection localities in Texas. A computer analysis of the resulting enzymatic variation in all specimens examined supports the existence of only a single species. Helicina orbiculata tropica Pfeiffer 1852 is synonymized with the nominate Helicina orbiculata (Say 1818)