THE OCCURRENCE OF MONOSTROMA AND ENTEROMORPHA IN OHIO1-2

1941, and is the only Ohio record of M. wittrockii known to me. Since this record was published, Monostroma bullosum (Roth) Wittrock and Enteromorpha intes-tinalis (L.) Greville have been collected in the Portage River at Elmore, Ohio. The location, in the extreme southwest corner of Ottawa County, is approximately three miles upstream from that where Monostroma wittrockii was discovered. The Portage River, at the village of Elmore, flows over an outcrop of limestone where bedrock is exposed during stages of low water. At such times the water flows through a number of shallow and irregular channels which vary in width from several inches to a few feet. The water is swift and turbulent because of the sharp dowstream declivity of the limestone outcrop and the irregular contours of the channels. Colonies of Monostroma bullosum were found attached to the limestone and to lodged driftwood in the swiftest and most turbulent water in the channels during August 1951 and 1954. The colonies, with diameters to 5 cm, were bright green, saccate, and mostly spherical to subspherical. Though their appearance in the current resembled somewhat that of young colonies of Tetraspora