Protologue Description: Forma atlanticum, n. f, Calyce nullo modo flavescente, lobis 5 vel 6, exterioribus albo-marginatis plus minusve rubescentibus, inter oribus albidis.-MAINE: Cumberland, in a hen yard, 31 Aug. 1901, E. B. Chamberlain ; Old Orchard Beach, 29 Aug. 1898, M. L. Fernald, no. 2729. MASSACHUSETTS : Edgartown, margin of salt marsh, 11 Sept. 1901, M. L. Fernald (type of form); West Falmouth, 16 Sept. 1894, J. R. Churchill; North Scituate, on brackish meadow, 6 Sept. 1897, W. P. Rich & E. F. Williams; Cambridge, marshes of the Charles River, 4 Aug. 1901; W P. Rich. RHODE ISLAND, Providence, on cove land, 10 July, 1892, J. F Collins. CONNECTICUT: Milford, on brackish marsh, 28 Aug. 1895, E.H. Eames; Bridgeport, salt meadow bordering Ash Creek (stems very brittle), 8 Sept. 1901, E. H. Eames. This form, although always recognizable by the color of its flowers, shows no constant morphological difference from the western typical form, which as stated above has been found at one station on Cape Cod: It bears also a very striking resemblance to the true P. Bellardi, All., of the Old World, which scarcely differs save in its more reduced subulate and slightly rigid floral leaves.