In earlier surveys of the phytoplankton of the Gulf of Maine (Bigelow, 1926 ; Gran, 1933; Braarud, 1934, Bigelow, Lillick, and Sears, 1940; Lillick, 1940) relatively few observations were made on Georges Bank, and the data obtained have not been ·sufficient to give an accurate picture of the development of the spring flowering in any part of this important bank region.