UNIVERSITY OF ' MICHIGAN

THIS paper is presented as a part of the co-operative efforts of a number of research workers to study the fauna of the Edwin S. George Reserve, Livingston County, Michigan. This area, which is maintained in a natural state by the Museum of Zool-ogy of the University of Michigan, comprises about two square miles of territory. I made collections of mollusks on the Reserve and took field notes in the fall of 1934 and again during an extended period from May to August, 1937. All specimens collected were brought in from the field for study in the laboratory. The plant-animal communities were surveyed by covering sample areas as thoroughly as possible; the transect method was mainly depended upon for ecological data. ACKNOWLEDGMENTS I am indebted to F. M. Gaige, of the Museum of Zoology of the University of Michigan, for various helps and kind-nesses, and to Calvin Goodrich, of the same institution, for * A contribution from the Edwin S. George Reserve. 2 Allan P. Arche