OF SOUTH AUSTRALIA. 
389 
sori or subimmersed in conceptacles or superficially grouped. 
Lithotlvamnion Philippi. Sporangia more or less oblong, trans- 
versely divided into two-four spores, in superficial conceptacular 
sori or subimmersed (pericarp with numerous osteoles). 
bb. Tetrasporangia evolved in proper conceptacles. 
,c. Thallus constantly of a single layer of cells, cuticle present or 
absent, pluristromatic around conceptacles. 
Melobesia Lamouroux. Thallus heavily incrusted with lime, 
cc. Thallus everywhere pluristromatic, cuticle absent or present, 
d. Thallus flexible (slightly incrusted). 
Mastophora (Decne.) Harvey. Fronds of thallus large and 
partly free; below stipitate, above complanate and more or 
less furcately branching, 
dd. Thallus not flexible (strongly incrusted). 
Lithophyllum Philippi. Sporangia collected in the marginal 
region of the disc. Pericarp with a single osteole. No hetero- 
cysts in the thallus. 
Goniolithon Foslie. Sporangia sparse over the whole bottom 
of the conceptacle. Pericarp with a single osteole. Hetero- 
cysts in the thallus numerous or sometimes sparse. 
aa. Thallus articulate, erect, terete or complanate, heavily incrusted, nodes 
not incrusted. 
Amphiroa Lamouroux. Cystocarps protruding, verrucose, sparse and 
superficial on the articulations. 
Cheilosporum (Dene.) Areschoug. Cystocarps terminal, immersed in 
the apices of horn-like processes. 
Corallma (Tourn.) Lamouroux. Cystocarps terminal, immersed in 
apices of the articulations. Branching pinnate, irregular, or tri- 
chomotous. 
Jania Lamouroux. Cystocarps terminal, immersed in apices of the 
articulations. Branching regularly dichotomous. 
ARCHAEOLITHOTHAMNION (Rothpl.) Foslie. 
Frond sublithothamnion, that is inarticulated, with a calcerous crust. 
Sporangia cylindrical-reniform, rotund-ovate, undivided, or cruciately 
divided ; sori in zones, conceptacles subimmersed or superficial, more or less 
regular, with a single apex, elongate, joined together with a muciform 
covering and separated by continuous walls, at length vanishing. Carpo- 
spores in superficial conceptacles, furnished with a thick apical pore. 
Archaeolitiiothamnion mirabile Foslie. 
Outer crust more or less orbicular, margin entire or irregularly dentate, 
or lobate ; on account of the many crusts or layers the matrix is often quite 
covered over; it is up to 1| cm. thick, somewhat shiny, here and there 
irregularly and minutely verrucose. Colour yellowish, greenish, or pink. 
Victoria (Phillip Island). 
