262 Poke tsar 
thickening discernable in the walls of the inner 
EoOMicaleeelils: 
Hotprast. The holdfast is made up of 
thin walled cells continuous with the cortex 
of the stipe. They are arranged in radial lines 
centering in the base of the center of the hold- 
fast, i. e. the original position of the primitive 
disc.\ Into this mass of cortical tissue extends 
the cylinder of pith from above, which gradually 
narrows and vanishes downwards. As described 
above, regions of local increase in thickness 
are often present. Sometimes this local growth 
may even be so active as to give rise to a branch 
which grows out from the main disc but is so 
closely appressed to it as to be unnoticeable 
except in section. (Piave shh vines 23) ae 
The lamina (Plate LM., fig: 1)( bene senate 
than in most of the kelps, is but a few (14-18) 
cells thick. The pith-web is extremely thin and 
there is no sclerenchyma. In the fruiting area 
nothing unusual was observed. 
Hapitat. Renfrewia parvula grows in the 
sublitoral zone in the tide pools and _ recesses 
never uncovered even at the lowest tides. It 
