Two species of the genus Vaucheria, V. lii Rieth and V. racemosa (Vaucher) DC., are reported from Connecticut and New England for the first time. Despite sampling over 150 freshwater habitats in Connecticut, each species has been located only at a single site. Culture conditions in the laboratory stimulated growth and, after extended periods of time, the production of gametangia allowing for the identification of each species. Despite its worldwide distribution, V. lii is shown to be a rarely collected species throughout its range.