ZL. 
22, 
23. 
24. 
Dee 
26. 
133 
Plants of conspicuously bright red colour, usually dichotomously 
branched and uncorticated, growing in stiff tufts, 2-6 inches 
long; reproductive organs in groups on special branches 
with short lateral pedicels and surrounded by a whorl of 
claw-like investing filaments; ‘“‘cells”’ of the filaments 
enormously large... ~ eats = Griffithsia ...p. 
Plant not as above ... 
Plant 2-4 inches long, uncorticated except for a few rhizoidal 
filaments at the base of the main axes; large-celled, bearing 
ovoid monospores (or occasionally tetraspores) on the inner side 
ofclustered branches; cystocarps invested by a whorl of single- 
celled filaments of large size joe Aas Monospora ...p. 
Plant with lateral branches whose proximal half is bare, but 
pinnately branched in the distal half; tetraspore mother- 
cells divided up by many radiating walls into a large number 
of polyspores ; cystocarps terminal, surrounded by a whorl of 
one-celled branches ie Gr ... Pleonospovium ...p. 
Bright red plants, 2-4 inches long, much branched, each branch 
ending in a hair; tetraspores as lateral branches; but plant 
more commonly reproduces by chains of ovoid “ seirospores,”’ 
formed by transformation of the cells of terminal dichotomous 
or trichotomous branches Be 566 Seivosporva ...p. 
Plant showing branching in one plane; bi-, tri- or quadri- 
pinnate, with terminal tetvaspores on ultimate pinnules 
Compsothamnion ...p. 
_Much-branched plant with tetrahedrally divided tetraspores 
arising laterally ; cystocarps usually in pairs, one on each side 
of the filament ; cystocarps without investing filaments 
Callithamnion ...p. 
Plant fundamentally of a polysiphonous axis with a central row 
of cells, each of which is surrounded by a varying number of 
pericentral cells of equal length ; the polysiphonous axis may 
be hidden by a mantle of small corticating cells 
Plant cylindrical, or dorsiventrally flattened, but Pen nene ally 
of a monosiphonous axis, partially covered by bands of 
small cells, or completely enveloped in a sheath of irregular 
corticating cells 
Plant wth polysiphonous main axes but with persistent mono- 
siphonous lateral branches 
Plant polysiphonous throughout except fe terminal groups of 
colourless hairs sometimes shed at maturity 
Thallus flattened in one plane 
Thallus branched in all planes 
Ultimate branches in the form of slender colourless hairs with 
elongated cells; tetraspores singly in rows in the distal 
. Heterosiphonia ...p. 
94 
22 
94 
94 
7) 
95 
24 
28 
25 
27 
93 
26 
portion of branches site res ... Brongmiartella ...p.92 
