The Peridiniales of Plymouth Sound from the Region beyond the Breakwater

Abstract

The following list includes all the Peridiniales identified in the plankton throughout the year from September, 1915, to September, 1916, from the water samples, details of which will be found in another paper in the same journal (p. 133). Also from the plankton in the tow nets in the same year and a portion of the summer 1915. As is shown in the abovementioned paper, the summer is the time for nearly all the Peridiniales, June being the maximum month. After October very few are seen in the water samples, although in the tow nettings the larger and stronger forms, such as Ceratium and Peridinium, are still present.