This report describes part of the research-in progress since 1969 at UMBS-on the ecology, life history and behavior of 5 species of Douglas Lake pulmonate snails. It is hoped that this study will give more complete answers to such questions as (1) Do pulmonate snails in lakes undergo seasonal migratory movements...? (2) If so, (a) are such migrations more characteristic of some species than of others? (b) At what time during the season do the major migratory movements take place, and how fast do the snails move? (c) How do these movements correlate with life history changes and density changes through the season? (d) What triggers these movements?