34 
Geo. K. Sutherland. 
and air, without any means of renewing their water supply. They 
are submerged at most only for a few hours each day, while during 
neap tides the water may not reach them for two, three, or even 
four days. This holds only during fine weather ; when the sea is 
rough the plants become drenched with spray or foam, even when 
the tides are neap. The result is that Pelvetia normally spends 
the greater part, and periodically the whole, of each day under 
conditions very similar to those enjoyed by many lichens to which 
its thallus bears a strong external resemblance. 
The abundance and wide distribution of Pelvetia., coupled with 
its amphibious habit, tended to mark it out as a possible and likely 
fungus host, an initial hypothesis which has been fully verified by a 
systematic examination of this alga throughout the past year. It 
has been found to possess a rich fungus flora, hitherto undescribed. 
Some are saprophytic, some parasitic. One symbiotic species is of 
special interest as its occurrence throws a new light on Pelvetia, 
opening the question whether it should be regarded as a lichen 
rather than an alga. 
MYCOSPHJERELLA PELVETIJE NOV. SP. (Fig. 1, 1—4). 
Mycelium hyaline, septate, very slender, diffused and entirely 
intercellular. Perithecia minute, 65-85 /x, spherical, with small 
conical tip, densely aggregated on receptacle. Perithecial wall 
