into a long cylindrical neck; spores minute, of various shapes, densely 
crowded into a spherical mass. Sfichidia borne on the ramuli, elliptic- 
oblong, with a sharp point, laxly cellular, containing three or four rows of 
roundish tetraspores. Zuées in the stem five, surrounding a cavity. Sud- 
stance rather crisp, becoming soft on exposure, and closely adhering to 
paper in drying. Colour variable; sometimes clear crimson-lake ; at other 
times more or less tinted with brown or yellow, and sometimes dark brown. 
In all cases the frond discharges a fine crimson powder on maceration in 
fresh water. 
enn 
This pretty plant was originally discovered by Messrs. Hooker 
and Borrer on the shores of the Orkney Islands, and has been 
found at various places along the western shores of Britain, to 
the extremity of the Land’s End. Its most abundant stations, 
are on the west of Ireland, in several bays of which coast it 
reaches a large size. On the Continent it has been found along 
the coasts of France and Spain, and in the Mediterranean. 
There are two principal varieties of this species ; one of them 
found on rocks near low-water mark, the other dredged in 
deeper water, and often on a sandy or shingly bottom, or among 
Zostera. In the first, which is represented in our figure, the 
frond is more robust and bushy, the branches more regularly 
alternate, and the colour frequently very dark. But this last 
character varies according to minor circumstances of each locality. 
This variety is frequently found in fruit, the pods being more com- 
monly found than the capsules. In the second variety the stems 
are more slender, the branches much divaricated, and the order 
of branching more or less dichotomous, while the ramuli are 
less dense, and more squarrose, and so far as I know, always 
barren. At first sight such specimens might pass for a different 
species, but there are innumerable intermediate forms. 
The D. scoparia of the Cape of Good Hope, and D. collabens 
of New Zealand nearly resemble this species in habit, but differ 
by some seemingly essential characters. 
Fig. 1. Dasya arBuscuLa :—of the natural size. 2. A branch bearing stichidia. 
3. Ramulus from the same, with two stichidia. 4. Tetraspore. 5. Branch 
bearing ceramidia. 6. A ceramidium from the same, on its stalk. 7, Trans- 
verse section of the stem :—all more or less magnified. 
