OVER-REPRESENTATION OF RARE ALLELES IN JUVENILES AND LACK OF PATTERN IN GEOGRAPHIC DISTRIBUTIONS OF ALLELES IN A LAND SNAIL

Eight populations of Mesodon zaletus (Binney) (Gastropoda: Stylommatop hora: Polygyridae), ranging from West Virginia to Alabama to Missouri and Arkansas, were examined at 16 allozymic loci, nine of which were v ariable. Available population samples were generally small (2-17), but a large sample (140) was taken from Monte Sane, Alabama. Chi-square t ests using PGM-1 in this population showed a fit to Hardy-Weinberg equ ilibrium, and an over-representation of rare alleles in juveniles. Amo ng the eight populations, M. zaletus showed substantial geographic dif ferentiation in allelic frequencies, with no consistent pattern of geo graphical variation among loci. These results put important caveats on allozyme systematics of land snails.