but have reason to believe it subsequent to the publication of the 
Englisn station. Mr. Mc’Calla was the first to detect it on the 
Irish coast, in the year 1840, and to him we owe the knowledge 
of its occurrence in plenty in Roundstone Bay, county of Galway. 
He describes it as covermg the bottom of the bay im wide spread- 
ing strata, at a considerable depth for an individual of this genus, 
and as being, towards the close of the summer, washed up in 
very large quantity, so as to be carted off by the country people 
for manure. ‘This will sound strangely in the ear of an English 
botanist accustomed to save the minutest scrap as a prize, or to 
spend hours in the disentangling of a specimen rolled tegether 
by the waves; but Mr. Mec’Calla’s statement is confirmed by our 
friend Mr. Andrews, who observed it cast up in similar abundance 
at Arran. 
No species can be more distinct. The very patent, opposite 
branches, and the mvariably opposite, distichous, horizontal ramul 
are its peculiar characteristics. It is most nearly related to C. Hut- 
chinsie and C. diffusa, of which it has the size, rigidity, and some- 
thing of the habit. But the opposite ramuli clearly separate it 
from either. Both the varieties represented im our plate are 
from Roundstone Bay. 
I cannot find that it has been noticed in any continental 
work. The name, given by Chauvin, under which it was re- 
ceived from M. Lenormand by Mr. Berkeley, does not appear to 
have been published, and this is the only continental authority 
which I have been able to ascertain for the species. 
Fig. 1, CLADOPHORA RECTANGULARIS, var. a :—natural size. 2. Portion of 
the same :—inagnified. 3. Var. 8 :—natural size. 4. Portion of the same :— 
magnified. 
