AP. 
28. 
20. 
30. 
Bits 
134 
Ultimate branches coloured, stout, curved and pointed ; tetra- 
spores arranged in whorls, 5-8 in a whorl on special cylindrical 
branches with slender pedicels ... ee -. Dasya ...pJgz 
Thallus branched in one plane forming fern-like fronds bi- or 
tri-pinnately divided ; or corticated entirely with the excep- 
tion of ene branches, but with polysiphonous main axis 
discernible . De oes .... Plerosiphoma ...p2o2 
Thallus Sylinaredl unbranched, polysiphonous but uncorticated 
except for main axis; frequently beset with groups of 
colourless hairs at the branch apices... Polysiphomia ...p.90 
Thallus cylindrical with a group of 5-6 central siphons well 
covered by a corticating layer several cells thick; branches 
attenuated at point of insertion ; tetraspores embedded in 
cortex of ultimate branches ; antheridia terminal in groups ; 
cystocarps lateral ... =f sists Ba Chondria ...p.89 
(See Note 16, p. 116) 
Thallus cylindrical with a few rows of elongated cells in the 
centre, surrounded by a cortical mantle several cells in thick- 
ness (longitudinal section does not show central and peri- 
central cells of uniform length with their crosswalls in the 
same planes) sure Bes Be sos Rhodomela_ ...p.88 
(See Note 17, p. 116) 
Thallus cylindrical ... eS siete sik ip fase a oe 
Thallus dorsiventrally flattened ... bac sais as .. 2g 
Thallus tough, irregularly pinnately divided, dark in colour or 
multi-coloured ; branches of varying width Gelidium ...p. 80 
Thallus rigid, usually stiff enough to maintain its shape when 
held out of the water; regularly pinnate with alternate long 
and short branches corticated to their tips .. Pilia ~~. pase 
Thallus soft, clinging to the fingers; branches of unequal 
length, but not regularly ae and short ; youngest branches 
monosiphonous ... sae Plumaria_ ...p.97 
Whole plant covered with none spine-like opposite branches 
lying in one plane; cystocarps terminal on short lateral 
branches ... oe ae Be Bonnemaisonia ...p. 88 
Plant cylindrical, branched in one or in all ae but main axes 
not flattened te 31 
Whole plant covered oe ee spine- Site oppose Peis 
lying in one plane; cystocarps terminal on short lateral 
branches |... oe es ea ... Bonnemaisonia ...p. 88 
Axial row of cells clearly discernible, either showing through 
the cortex or giving a “‘ beaded’ articulated outline to the 
plant male sh 7 es net os | 3a 
Axial row of cells not sieee shoo ee in very young 
branches ... Be see ohre ies ak ies . Be 
