NEW BRITISH MARINE ALGjE. 
95 
removing them from among the red sea-weeds. The author has 
united the genera Diploderma , Kjellm., with the much older genus 
Porphyra , A g., as he does not regard the diplostromatic nature of 
the frond, a character on which the genus was founded, as constant. 
He also regards D. amplissima , Kjellm., D. tenuissima , Stromf., 
and P. abyssicola, Kjellm., as simply forms of one polymorphic 
species, P. miniata , Ag. 
A new species of Laminaria — L. grcenlandica — which may, how- 
ever, prove to be only a young state of L. caper ata , De La Pyl., 
and a new Myriocladia — M. callitricha — characterized by the frond 
being thickly clothed with long, simple or branched, coloured hairs 
are also described. The author has been fortunate enough to 
discover plants belonging to no fewer than four new genera, the 
diagnoses of which are given in his book. Three of these, Ccelo- 
cladia , Omphalophyllum , and Symphyocarpus belong to the Phceo- 
pliycece , the remaining one ( Chcetobolus ) to the Chlorophycece. 
In the first of these genera, Ccelocladia , the frond is filiform, 
branched, and hollow ; the growth trichothallic. The plurilocular 
sporangia shortly cylindrical, covering the whole surface of the 
frond, usually 1-4 laterally connate. The genus contains one 
species, C. arctica. 
The second genus, Omphalophyllum , is thus diagnosed. Frond 
most probably at first saccate, then torn and plane ; when old 
shortly umbilicately stalked. Membranous, composed of 1-2 strata 
of cells ; hairs wanting. Unilocular sporangia scattered, of the 
same form as the vegetative cells. The single species described is 
O. ulvaceum. In Symphyocarpus , the other new genus of Phceo- 
phycece , the frond forms an incrustation composed of a basal 
stratum, from which erect filaments arise. Basal portion formed 
of a single layer of creeping filaments, at first free and arranged 
in an irregularly radiating manner, then confluent. Erect filaments 
very short, of equal length, simple or subdichotomous, free, but 
very closely packed together. Each cell contains a single disc- 
shaped apical chromatophore. Plurilocular sporangia, oblong- 
ovate, situate at the apices of the erect filaments, 2-4, laterally 
connate, opening at the apex. The genus contains a single species, 
S . strangulans. 
The new genus Chcetobolus is thus described. Frond 
epiphytic, usually nearly hemispherical, more rarely sub-globose. 
Cells divided in all directions. In the hemispherical fronds 
the basal margin is composed of a series of sub-radiating 
cells. The superficial cells (with the exception of the marginal 
ones), if not covered with other algas, are drawn out into a long 
inarticulate apical tube, which is not separated by a septum from 
the cell which bears it. Propagation, most probably, by zoospores 
formed in the superficial cells. Ch. gibbus is the only species. 
In addition to the genera above mentioned Herr Rosenvinge 
forms a new genus, Gayella , for the reception of the Schizogonium 
radicans of Foslie, and the Ulothrix discifera of Kjellman. The 
