90 
ALGAS. 
A similar dilatation in E. ramellosa , Kiitz., from Kerguelen’s 
Land, is figured in Kiitz., Tab. Phyc., Yol. vi., p. 41, f. 3. 
In some respects the plant bears a superficial resemblance to 
Letterstedtia insignis , but I have not observed any trace of the 
mode of development of branches characteristic of that plant, 
viz., from lateral fissures in the main frond, and the cells are not, 
as in L. insignis, vertically twice as long as broad and densely 
packed with endochrome, but are often twice as broad as long, 
with the endochrome not filling the cell. The cell-walls of E. 
rhacodes appear to swell in fresh water and give a gelatinous 
appearance to the plant, which, however, disappears in drying. 
This plant seems to bear the same relation to E. clathrata that the 
E. subsalsa of Kjellman (Alg. Arct. Sea, p. 292, Tab. 31, f. 1) 
bears to E. micrococca, Kiitz. 
NEW BRITISH MARINE ALGiE. 
By E. A. L. Batters, B.A., LL.B., F.L.S. 
Pleurocapsa amethystea, JRosenv., Gronlands Eavalger ( ScertryTc af 
Meddelelser om Gronland, in.), p. 967. 
Colour dirty violet, vegetative cells at first solitary, round, or by 
the mutual pressure of adjacent cells angular, when seen from 
above, 10-13 /x in greatest diameter, hemispherical, compressed or 
subglobose. By repeated vertical and horizontal division of the 
cells hemispherical or subglobose families, 45 p or more in 
diameter, are formed. By the final divisions minute spores, 1-2 fx 
in diameter, are formed. 
Hab. On the fronds of lihizoclonium riparium. 
The above description, which is a translation of Rosenvinge’s 
diagnosis of the species, exactly describes a plant which we 
gathered in June, 1890, at Puffin Island, off the coast of Anglesey. 
The plants grew on and over the filaments of Urospora Jlacca, 
Ehizoclonium riparium , and other high-water species, either 
singly or in small groups, and were of a dirty violet colour. The 
habit of the plant and its colour at once distinguish it from 
Pleurocapsa fuliginosa. We have received specimens, also from 
Puffin Island, of what appears to be the same species from Mr. 
Harvey Gibson. 
Rhodoohorton membranaceum, Mag., f. macroclada, Rosenv., l.c., 
p. 794. 
M. Rosenvinge has given this name to those specimens of E. 
membranaceum in which the tetraspores are borne on free exserted 
filaments, sometimes consisting of as many as 40 cells, 6-8 p in 
diameter. The specimens of this species mentioned as occurring 
at Berwick (Batters, List Mar. Alg., Berwick, p. 101) are refer- 
able to this variety, as are also the specimens from Brighton in 
my copy of Holmes’ Algae Britannicae Rariores exsiccatae, part vi. 
On the other hand, specimens gathered at Cumbrae are certainly 
