Following is a continuation of the list of titles and authors of the papers presented: Chlorophyll a Distribution in Lake Huron and Its Relationship to Primary Production. By W. A. Glooschenko, J. E. Moore, and R. A. Vollenweider. Toxic Heavy Metals in Relation to Lake Erie Herons. By R. D. Hoffman and R. D. Curnow. Seasonal Distribution, Composition and Abundance of Zooplankton in Ontario Waters of Lake St. Clair. By J. H. Leach. Tritium Cycling in a Lake Erie Marsh Ecosystem. By Jacob W. Lehman. Changes in Zooplankton Populations in Lake Ontario (1939-1972). By D. C. McNaught and M. Buzzard. Distribution of Benthic Invertebrates in the South End of Lake Michigan. By Samuel C. Mozley and Wayne P. Alley. Ponar Grab Modified to Take Three Samples in One Cast, with Notes on Ponar Construction. By Samuel C. Mozley and Orest Chapelsky. Environmental Testing of Citrate: Bioassays for Algal Stimulation. By A. G. Payne.