RHODOSPERME®. 93 
Lomentaria, is a summer annual, by no means abundant on our shores, 
though very common on the American coasts. It is easily distinguished 
from the others of its tribe by the much shorter joints of its stems 
_and branches, all of which are of nearly equal length and breadth, those 
in the ramuli being proportionally shorter, and the tips of the branches 
and ramuli obtuse or rounded; capsules, which are ovate or egg-shaped, 
are produced on the branchlets; tetraspores in the joints. Fig. 87 represents 
a branch or two of this species. JL. reflexa is the rarity of this genus. I 
have take it but once only, and that was during a dredging excursion at 
Plymouth, when it came up in the dredge attached by little root-like 
processes to a fragment of another alga. This species is very sparingly 
branched ; the branches being mostly what is termed ‘‘ secund,”’ or pro- 
duced on one side only of the stems. The ramuli spread out widely, 
or are curved slightly downwards, hence the specific name reflexa. 
Fig. 88. Laurencia pimnatifida. 
The genus Lawrencia, as recently revised by Professor Agardh, contains 
only three British species, all of which are more or less common; one, L. 
pinnatifida, being found in all seas, and is equally abundant in temperate 
and tropical climates. On our own shores this species is very common ; 
and indeed, it is so extremely variable in size and general appearance, as 
well as colour, according to the depth of water in which it grows, that 
botanists recognise and describe no less than three varieties. The typical 
form of this species, as represented in Fig. 88, rarely grows above extreme 
low-water mark; but in this situation and in deeper water it attains 
a length of 12in. or more, and is of a fine dark purple, or sometimes 
brown-red. As this species advances towards the shore it becomes stunted 
in form and size, though still preserving its characteristic appearance, 
