50. 
51. 
52. 
33: 
54. 
55: 
139 
Thallus hollow, or stem solid and branches hollow _... Fone 5a! 
Thallus solid throughout ... res Nae uae oa ese ae 
Thallus, at least the main branches of it, not obviously con- 
stricted into articulated joints; branched in one or in all 
planes ane = ee ote 2 See 52 
Thallus, both main sank and branches, definitly ruses 
into articulated joints... ‘ : ote ‘s oe Ge 
Thallus branched sparingly at the base, forming Neue of 
tubular, irregular and sometimes twisted branches, slightly 
flattened; 3-12 inches in length by + to 4 an inch in 
width ; dark purple-red or brownish in colour; built up of 
longitudinally running threads giving off short peripheral 
branches and covered by a layer or two of very small 
branches oe : ee ... Dumoniia ...p.100 
Thallus 2-6 inches.long, es ea: finely divided, usually in 
one plane only, but sometimes in all planes; bi- or tri- 
pinnate; each pinnule an elongated club-shaped branch, 
attenuated at both ends ea Lomentaria clavellosa ...p. 85 
Thallus $ to 14 inches long, consisting of a flattened ovoid 
frond, from the margins of which spring a small number (6-12) 
of similar branches oe <8 Lomentaria rosea ...p. 85 
Main stem cylindrical, closely beset at or near the apex with 
distended ovoid branches, on which or in which reproductive 
organs May occur ASE ae ... Chylocladia ovatus ...p. 86 
Very small plant, about ? inch in height; blackish, found in 
crevices of rock in upper half of littoral zone; thallus not 
completely hollow but traversed by a wide-meshed network 
of interlacing filaments; tetraspores zonately divided 
Catenella_ ...p. 83 
Plant 2-4 inches long, clearly and definitely articulated into 
bead-like joints, but branched more or less in one plane, 
forming fan-shaped fronds; articulations of main stem about 
Painceh imleneth «... seis ... Lomentaria articulata ...p.85 
Plant 5-12 inches long of pyramidal outline; branches arising in 
whorls of 3-6, secondary and tertiary branches similar ; 
articulations of main stem } to ? inch in length ae 
Chylocladia Re eras “Ep. os 
Plant 1-4 inches long, forming a dense tuft of spreading branches, 
whose segments, though definitely articulated, are not 
conspicuously swollen in their middle region Champia _...p.85 
Thallus less than 1 inch long, articulated into bead-like joints ; 
black or dark purple in colour se ... Catenella ...p. 83 
Thallus cylindrical or slightly aaa but not articulated 
into bead-like joints siete a): ae Bers gee) KS 
Thallus with sturdy cylindrical stems, 4 to } inch in diameter, 
3-6inches long, repeatedly forked ; terminal branches slightly 
swollen, reaching a uniform height and giving a very regular 
appearance to the plant ee ee das tee “oh 50 
