those of the ramuli generally with fewer tubes. Conceptacles ovate, termi- 
nating « ramulus, which is generally shortened to about half the length of 
a barren ramulus. Zetyaspores lodged in the ramuli, towards the base, the 
fertile portion generally tipped with a beak-like barren point. Colour a 
dark, rather dull purplish-red. Swdstance not very soft, long bearing the 
action of fresh water. In drying the frond adheres, but not very strongly, 
to paper. 
This pretty little species is common in Western Australia, 
where it was first detected by Preiss, creeping over various 
algee, which it sometimes closely covers with its parasitic surcull. 
It is allied to P. versicolor, but differs in substance, in ramifica- 
tion, and in size. It may also be compared with the Antarctic 
P. ceratoclada, and others of the section “ Pennate,” but ap- 
pears to be sufficiently characterized. As yet it has only been 
found on the west coast of the Australian continent. 
Fig. ]. PotystpHonta RostRATA, a tuft,—che natural size. 2. A frond, rising 
from the creeping stem. 3. Ramuli and a conceptacle. 4. Spores. 5. 
Section of a ramulus. 6. Section of the main filament :—variously mag- 
nified. 
