390 
THE SEAWEEDS 
LIT H 0 T H AMN 1 0 N Philippi. 
Frond calcareous, becoming stone-like, erect from the crusted hypo- 
thallus, tuberiform or bushy, simple or branched, subterete, with a double 
layer of cells ; the cortical cells almost hexagonal, the interior cells oblong- 
elongate, in transverse zones. Conceptacles of sporangia superficial or 
subimmer$ed, scattered over the frond, furnished with an apical pore. 
Sporangia zonately divided. Conceptacles of carpospores superficial or 
slightly immersed, conical or subconical, furnished with an apical pore. 
Lithothamnion Mnelleri Lenormand. 
Frond fucoicl, matrix enveloped, crusted ; ramuli cylindrical or flattened, 
arranged irregularly. Groups of cystocarps and sporangia in the same 
frond ; conceptacles prominent, abundant, subimmersed. Sporangia 
obovate, transversely divided in eight sections. Tetrasporangia minute and 
pyriform. 
Australia (Lyall Bay). 
Liihothamnion fumigatum Foslie. 
Frond crusted, with an indefinite outline, and small dense tubercles. Con- 
ceptacles of the sporangia slightly prominent, the centre frequently 
depressed. 
Victoria. 
Lithothamnion lichenoides (E. and S.) Heyclrich. 
Forming foliated patches from 2 cm. to 15 cm. or more in diameter, con- 
sisting of numerous overlaying laminae, variously lobed and concentrically 
striate, resembling a semi-foliaceous lichen. Cystocarps large and very 
prominent. Colour pale red or creamy. 
South Australia (Eastern Bays), Atlantic, Mediterranean, and Aus- 
tralian Oceans. 
Lithothamnion lichenoides var. Patena (H. and H.) Foslie. 
Syn. Melobesia Patena Hooker et Harvey. 
Fronds \ cm. to 2 cm. long, fixed by a groove in the base which clasps 
round the stem to which they are attached, otherwise free, horizontal, flat, 
or slightly concave, obovate or suborbicular, very entire, with a flat and 
slightly thickened margin. Cystocarps numerous, scattered, depressed. 
Colour a deep purplish-red. 
South Australia (South Coast of Kangaroo Island, Eastern Bays), New 
Zealand (usually parasitic on Ballia calUtricha ) . 
MELOBESIA Lamouroux. 
Frond flat, expanding horizontally, crustaceous, affixed below, formed of 
layers of cells arranged in flabelliform rows. Conceptacles of the carpo- 
spores superficial, conical or hemispherical-conical, furnished with an apical 
pore. Conceptacles of the sporangia superficial or slightly immersed, conical 
or hemispherical-conical, with apical pores. 
