110 BRITISH MARINE ALG. 
is a more delicate plant than P. urceolata, though its general appearance 
is very similar, and the structure is almost identical ; (c) is a section of 
the stem, highly magnified. The siphons are four in each of these plants, 
and the central tube, though small, is filled with endochrome. There is 
another variety of P. wrceolata, ca'led P. patens, from the patent or spread- 
ing character of its branches, which are often reflexed or curled at the tips, 
and it is very curious that although in the living state this yariety is a 
fine red, it frequently turns black in drying, the capsules contracting 
and appearing only as little black specks on the stems and branches. 
These plants, as well as P. fibrata, are annuals, and should be looked 
for in the spring and early summer. P. fibrillosa (Fig. 104) is another 
summer annual, which in some seasons is tolerably abundant, and is 
met with pretty generally on the British coasts. I have taken speci- 
mens of this plant at Hastings which were 12in. long, and frequently 
the fronds are found from 8in. to 10in. in length. The stem of 
this species is thick and very obscurely jointed, but when the terminal 
branches are examined, the articulations are more evident, and the ramuli 
are generally distinctly two-tubed, the siphons rather longer than broad. 
Tetraspores are produced in these terminal ramuli, which they distort 
greatly, as seen at a, Fig. 104, and the tips of every filament are crowned 
with tufts of branched and jointed fibres, a constant character which sug- 
gested thespecific name of this plant. P. elongata (Fig. 104), commonly known 
as the lobster-horn Polysiphonia, (the winter state of the long bare stems 
and branches being certainly very similar to the antenne of the lobster) 
is a hardy,’robust species, abundant in rock pools and in deep water. 
The summer and winter states of this species are widely different. As 
winter approaches, the ramuli fall away, leaving the lobster-horn stems 
bare and unsightly; but in the spring the branches put forth tufts of 
beautiful crimson filaments, each of which is tipped with finely attenuated 
fibres, the fruit being borne on the young tufted ramuli. There are several 
varieties of this species described by botanists; but I am inclined to con- 
sider them as merely different states of the plant, for in all I find the 
structure and fructification identical. All the branches and ramuli, but 
more particularly the latter, are attenuated at each extremity, an 
invariable character which greatly facilitates identification. The stem and 
larger branches of the plant are very indistinctly jointed, the surface cells 
being so small and so closely packed as nearly to hide the articulations 
and siphons. These are only distinctly apparent in the upper branches 
and terminal ramuli, as represented in a magnified sprig, at 6, Fig. 104. 
The ramulus to the left contains tetraspores, which appear like warty 
swellings produced alternately on each side of the stem. Winter specimens 
of this Polysyphonia adhere but imperfectly to paper; but spring and 
summer plants, when clothed with their flaccid multifid ramuli, are easily 
mounted, and form very attractive book specimens. Fig. 106, represents 
the charming little plant, P. parasitica, one of the most elegant of any of 
the very beautiful genus to which it belongs. Its usual place of growth is 
