388 
THE SEAWEEDS 
Peyssonnelia australis Sonder. 
Frond affixed at the base, otherwise free, coriaceous, dark red, flabelli- 
form, zonate, entire; the superior margin thin and often reflexed; the 
lower surface tomentose with reddish fibrils. Nemathecia scattered, purple. 
Attachment a disc. Upper surface of the frond glabrous; somewhat 
shiny and ridged at short intervals with lines of growth. The under surface 
thickly clothed, except on the younger portion near the edge, with a rusty 
tomentum of short, slender, jointed hairs. Substance leathery and tough. 
Does not adhere to paper. 
South Australia (Encounter Bay), Victoria, Tasmania. 
Fig. 196 . — - Peyssonnelia australis: a, plant; b, 
vertical section, showing the two 
strata of which the frond is composed, 
and some of the fibres of the 
tomentum. (After Harvey.) 
Family COR ALLIN ACEAE (Gray) Harvey. 
CONSPECTUS OF THE GENERA. 
Thallus provided with a basal disc, incrusted with lime. Rhizoids not 
penerating the matrix, 
a. Thallus inarticulate. 
b. Tetrasporangia in zone-like sori, or collected into conceptacles. 
Archaeolithotkamnion (Rothpl.) Foslie. Sporangia sub cylindrical 
or rotund-ovate, undivided or cruciately (?) divided, in zone-like 
