309 
British Marine Algae. 
ance. At first the young frond consists of a single row of 
cells which, by transverse and longitudinal division, very soon 
forms a solid axis of large, hyaline, more or less angular 
roundish cells surrounded by a cortical layer of much smaller 
cells furnished with numerous small disc-shaped chromato- 
phores. When the fronds have reached a few lines in length, 
the cortical filaments first make their appearance, commencing 
at the apex of the frond and gradually spreading downwards 
till the entire frond, with the exception of the basal portion, 
is covered. The base of the frond always remains slender, 
often consisting of a single row of cells, and is thickly covered 
with descending rhizoidal filaments, which, creeping between 
the cortical filaments of the host-plant, securely anchor the 
epiphyte in position. Hyaline hairs of the usual type are 
plentifully scattered between the cortical filaments. The 
slender assimilatory filaments are either simple or forked and 
are slightly clavate ; they generally consist of from three to 
seven cells about 9 \x in diameter. The cells vary in length 
from 10-18 /x, the longer being mixed with the shorter ones 
without any apparent regard to position, the terminal cell 
being either longer than the rest or slightly shorter than those 
immediately below it. 
Plurilocular sporangia are borne among the cortical fila- 
ments, and are either linear-oblong or spindle-shaped, obtuse 
or pointed, and always more or less evidently stalked ; 
sporangia consisting of a single row of superimposed cells are 
frequently met with. In length the sporangia vary from 
50-75 [x or even longer ; the diameter is usually about 15 /x. 
In some specimens the sporangia are as long as the cortical 
filaments, whilst in others they are rather shorter. 
Growth is basal. Very young specimens usually terminate 
in one or two hyaline hairs. 
Relying on the structure of the mature frond, I have, in the 
note above referred to, placed Buffhamia in the Chordariaceae : 
but, taking the development into consideration, I should pro- 
bably have done better had I made it the type of a new/amily, 
Buffhamiaceae. 
