a new Genus of E ndophytic A Igae . .187 
Although I have examined a large number of specimens of 
Cladophora pellucida , which is by no means an uncommon 
alga on the shores of both France and England, only on two 
occasions have I met with Schmitziella , which I therefore con- 
clude is a somewhat local plant The rarity of the alga is 
compensated for, in a certain measure, by the fact that where 
it does occur it takes possession of a large portion of the 
host-plant ; thus a single specimen of Cladophora pellucida 
which has been attacked by this endophyte often furnishes an 
abundant supply of material for purposes of study. 
The health of the Cladophora , to all appearance, is not in 
the least affected by the presence of the endophyte which is 
found equally in the cell-walls of both young and old speci- 
mens, its presence being betrayed by the beautiful red colour 
it communicates to their stems. So far as I have observed, 
the straggling deep-water form of the species is the most 
liable to be attacked. 
Both at Torquay and Puffin Island the infected plants were 
growing in deep rock-pools very much shaded by overhanging 
boulders, and owing to the depth of the water it sometimes 
happened that only the long secondary branches of the Clado- 
phora were obtained, and as these did not always exhibit the 
characteristic marks of the species I was at first misled into 
thinking that Schmitziella grew on more than one species of 
the genus. Up to the present, however, Schmitziella has been 
found only on C. pellucida , although I know of no reason 
why it should not occur on other species, or at any rate 
on those with a perennial base, such as C. catenata or C. 
prolifera. 
As so often happens with specimens of C. pellucida, the 
plants which had been attacked by Schmitziella were also 
more or less covered with encrusting Melobesiae, but the 
purplish, chalky fronds of the epiphytes could not for a 
moment be mistaken for the rose-red, delicate thallus of the 
endophytes. The action of light does not appear to be 
necessary for the healthy development of Schmitziella, for on 
removing the chalky and nearly opaque fronds of the Melo- 
o 
