104 
algj:. 
Phceophila floridearum those of Rodymeniae, and other Florideas 
are examples of parasitic Chlorophycece, which, perhaps, extort 
nothing beyond lodging from their hosts. Amongst the Phaeo- 
phyceae, however, the case of some Ectocarpi, Elachistese, and 
Litosiphones is rather different, for here, while the principal portion 
of the plant is quite external, rootlets are sent deep down into the 
tissues of the host-plant, in some instances distorting them and 
forming a “ gall.” Of plants of this kind we have in Britain 
Ecto carpus brevis on Ascophylla, Ectocarpus luteolus on Fuci, Ect. 
minimus on Himanthaliae, Ect. parasiticus on Ceramia and Cysto- 
clonia, Ect. investiens on Gracilariae, Ect. velutinus on Himanthaliae, 
Myriactis stellulata on Dictyotse, Litosiphon laminarice on Alariae, 
etc., while amongst Algae which have not yet been detected on our 
shores, but which may be confidently expected to occur, we may 
mention as of especial interest Ectocarpus valiantei and Streblo- 
nemopsis irritans, which form together with the distorted cells of the 
host-plant gall-like excrescences on Cystosirae ; and Ect. solitarius 
on Taoniae. Amongst the Florideae true parasites are not uncommon; 
we may instance Choreocolax polysiphonice living in the tissues of 
Polysiphoniae and causing gall-like excrescences on their fronds, 
Harveyella mirabilis , causing similar galls on Rhodomelas, Actino- 
coccus roseus on Phyllophora, Gonimophyllum Buffhami on Nito- 
phylla and Choreonema Thuretii on Corallinae, while Schmitziella 
endophloea may be taken as an example of one of the endophytic 
Florideae, probably seeking only lodging from its host Cladophora 
pellucida. The above list is sufficient to show how numerous are 
both semi and truly parasitic Algae. 
Notes on Scotch Fresh-Water Algce. By W. West. (“ Journal of 
Botany,” April, 1893.) 
Mr. West gives us in this paper a list of some 216 species and 
varieties of fresh-water Algae, partly gathered by himself during a 
short botanical tour about some of the mountains of Scotland, in 
July, 1889, and partly by Mr. Naylor in the Orkneys. The paper 
is illustrated by an excellent plate drawn by the author’s son. 
The following new species and varieties are described : — 
(Edogonium Itzigsohnii, Be Bary ; var. minor, West. 
Var cum cellulis augustioribus et oosporis minoribus. Crass, 
cell, veget. 6-6’5 p ; altit. 8-10 plo. major ; crass, oogon. 30 p; 
altit. 28-30 p ; crass, oospor. 18-20 p ; altit. 18-20 p. Orkney 
Islands. 
Oocystis apiculata, West. 
O. in familas e 2-4 cellulis formatas consociatis, oblongis, 
diametro duplo longius, subapiculatis et incrassatis ad unumquem- 
que polum. Long. cell. 11-15 p ; lat. cell. 5-6 p ; diam., fam. 
2-cell., 22-24 p. Orkney Islands. 
