J 
OF SOUTH AUSTRALIA. 183 
Subfamily Melanthaleae J. Agardh. 
MELANTHALIA Montague. 
Frond linear, piano-compressed, dichotomous and fastigiate, solid, 
coriaceous, densely cellular, of two strata, the medullary of elongate angular 
colourless cells, the outer ones shorter ; the cortical of very minute, coloured, 
vertically seriated cellules. Cvstocarps marginal, hemispherical, thick- 
walled, bearing, on a basal placenta, densely tufted moniliform spore- 
threads, at length separating into minute spores. Tetrasporangia evolved 
in thickened, sub-club-shaped apices of brandies (nemathecia) , cruciately 
( ?) divided. 
Melanihalia obiusata (Labillardiere) J. Agardh. 
Frond elongate, 10 cm. to 60 cm. long, repeatedly dichotomous and flabel- 
liform ; segments 2 mm. to 4 mm. wide, linear, two-edged, bluntly truncate. 
Substance very tough, leathery. Colour brownish-purple, tending to black. 
Growing on rocks a little below low water. 
South Australia (Encounter Bay, Investigator Strait, Eastern Bays), 
Victoria, Tasmania. 
Fig. 51 . — Melanthalia obtusata: a, plant; b, branch of 
var. intermedia ; c, horizontal section of a 
conceptacle and portion of the branch; d, 
some spore-threads from the nucleus. 
(After Harvey.) 
