Various species of freshwater operculate and pulmonate snails show marked differences in rate of dispersion, total distance moved and direction of movement. Field experiments conducted between July and August 1982 showed that forty-eight hours after release, Goniobasis livescens traveled the greatest distance and had the largest percentage of snails that moved a minimum of 1 m. In contrast, Helisoma anceps dispersed the least with only 5% moving past one meter during the same time. The longest distance moved by any H. anceps was 1.6 m. Physa integra and Lymnaea catascopium were similar in the rate of movement, but differed in the total distance traveled. Finally, variations in direction of movement were observed among the four species. Both P. integra and L. catascopium moved up the slope (toward shore); however, G. livescens preferred to move away from shore to deeper water; H. anceps appeared to show no directional movement.