16
THE MARINE ALGAE OF ESSEX.
GYMNOGONGRS, Mart.
Gymnogongrus griffithsiae, Mart., "Flor. Brasil.," p. 27.
Felixstowe and Dovercourt, G. P. Hope.
G. norvegicus, J. Ag., "Spec. Alg.," ii., p. 320.' Felixstowe,
G P. Hope and E. A. B.
 AHNFELTIA, Fr.
Ahnfeltia plicata, Fr., "Fl. Scand.," p. 310. The first record
of this as an Essex plant is in Ray's "Synopsis," ed. ii., p. 4, where
the following passage is to be found: "Alga exigua dichotoma
arenacei coloris. Small sandy or amber-coloured wrack. In littore
Essexiano non procul Harvico collegit D. Newton prope Walton
vicum." Several specimens preserved in the Buddie and Petiver
collections ("Herb. Sloane," vols. 114 and 150, Brit. Mus.) prove
that Ahnfeltia plicata is the species referred to. The plant still
grows in the same neighbourhood, for there is a specimen with the
hote, "On round flints at Felixstowe," in the Hope collection. The
plant is also to be met with at Southend and Clacton.
(In a recent paper ("Flora oder Allg. Bot. Zeitung," 1893, heft 5,
pp. 368-418) Prof. Schmitz asserts that what have been considered
asexual reproductive organs (nemathecia) of Gymnogongrus griffithsiae,
G. norvegicus, Phyllophora rubens and Ahnfeltia plicata are really
parasitic Floridere. Of these parasites the following occur in Essex.
ACTINOCOCCUS, Schmitz.
Actinococcus aggregatus, Schmitz, l.c, p. 385. On G.
griffithsiae, Felixstowe, G. P. Hope.
Actinococcus peltaeformis, Schmitz, l.c, p. 387. On G.
norvegicus. Felixstowe, E. A. B.
 COLACOLEPIS, Schmitz.
Colacolepis incrustans, Schmitz, l.c, p. 417. On Phyllo-
phora rubens. Clacton, E. A. B.
STERROCOLAX, Schmitz.
Sterrocolax decipiens, Schmitz, l.c. p. 397. On Ahnfeltia
plicata. Felixstowe, G. P. Hope.)