46. 
47- 
48. 
49. 
138 
Plant rose-coloured, almost transparent ;- transverse section 
shows four rows of cells only, of which the two innermost are 
rectangular in outline and very large; superficial tissue a 
single layer of very small cells...  ... Halarachnion ...p. 101 
Plant dark red in colour, at least at the base, sometimes freely 
proliferating from the margin ; transverse section shows central 
tissue of large rounded colourless cells ; tetraspores cruciately 
divided ... ssi 2 aot stag Rhodymenia ...p.84 
Large membraneous ne of stout texture, usually undivided 
though sometimes lobed; central tissues of longitudinally 
elongated and interwoven filaments covered by cortical layers 
efzsmall’ cells = 2s bs co .. Callymenia_...p. 82 
Thallus bright red, opaque, hoa dichotomenee divided, 
spreading out fan-wise ; frequently with proliferations from 
the margins... we Eats ane Callophyllis ...p.82 
Thallus extremely delicate in texture; the greater part of it 
one cell only in thickness; variously lobed and divided ; 
sometimes with short irregular veins ; apical cell not distinct ; 
tetraspores tetrahedrally divided ; cystocarps scattered over 
the frond ist i ee Nitophyllum  ...p. 86 
Thallus several cell Cae in tnnchnes AS oes da ve 948 
Large membraneous algae of stout texture, undivided or 
irregularly lobed ... — aE Es ae aoe «. 49 
Thallus bright-red, opaque, broad, dichotomously divided, 
spreading out fan-wise ; frequently with proliferations from 
the margins ; cystocarps and tetraspores scattered over the 
thallus or localised on the proliferations Callophyllis ...p.82 
Thallus very delicate in texture, pale in colour, very finely 
divided into narrow ribbon-like segments, quarter inch in dia- 
meter, often toothed ;_ cystocarps large and prominent on the 
margins of the fronds; tetraspores relegated to the tips of 
the ultimate branches ; longitudinal section shows a medulla 
built up of dichotomously branched rows of large cells 
Euthora ...p. 83 
Thallus of delicate texture divided into lobes that are frequently 
dichotomous; growing in almost spherical masses 2-6 inches in 
diameter ; zonate tetraspores mostly on the tips of the fronds ; 
cystocarps scattered along the margins ; longitudinal section 
of the medulla shows a central filament of elongated cells 
giving off alternate branches ae Rhodophyllis ...p. 83 
Thallus with an elongated lanceolate blade giving off irregularly 
(sometimes pinnately) marginal tongue-like branches 
Calhiblepharis ...p.84 
Central tissue of longitudinally elongated and interwoven 
filaments covered by cortical layers of small cells 
Callymenia_ ...p. 82 
Central tissues of large rounded colourless cells clearly visible 
through the superficial layers of small cells Rhodymenia ...p.84 
