twice as long as broad. Colour a brownish-red, purplish when dry. 
Substance between cartilaginous and membanaceous, adhering to paper. 
Nar PAL PAPP ALA PPALLLS LAL LIP ALAL 
I here figure a plant which in the ‘British Flora’ I had in- 
correctly referred to C. granulatum, Ag., a species which I 
now know to be much more nearly allied to our C. spongiosum. 
In the ‘Manual’, I have been content to regard the present as 
merely a slender variety of C. tetragonum, with which it is very 
commonly confounded, and which it resembles in most of its 
essential characters, and in general aspect can hardly be distin- 
guished, except on a close inspection. My friend Professor J. 
Agardh, however, has judged differently, and done me the honor 
of giving it my name, in which he has been followed by Endh- 
cher, in his useful Synopsis. My attention is thus again directed 
to the subject, and I have deemed it best to give a figure in 
which all the characters by which it differs from C. tetragonum 
being depicted, botanists may form their own opinion as to the 
validity of its claims to rank asa species. I should have adopted 
the specific name of Agardh, had J not received from M. Lenor- 
mand specimens, exactly similar to our British ones, bearing a 
name conferred by Bonnemaison, which, I believe, has priority 
to that proposed by Agardh, though at present I am’ not aware 
where it has been published. ; 
The character by which C. drachiatum appears essentially to 
differ from C. te¢tragonum, is to be found in the ultimate ramuli, 
which in this are constantly subulate, gradually tapering from the 
base to the apex; and in that are suddenly acuminate, or, as 
it were, mucronate. This is what originally induced me to admit 
the species, which I found indicated in the unpublished ‘ Algee 
Appinenses ’ of Carmichael, under the name C. /ruticulosum ; and 
so far as my observations have gone, this character appears to be 
constant. Minor and less important distinctions may be taken 
from the length of the joints, and their form, which is cylindrical 
in the present species and oval in C. ¢etragonum. Both plants 
are equally common, and found in the same situations. 
Fig. 1. CALLITHAMNION BRACHIATUM :—of the natural size. 2. Penultimate — 
branches. 3. A plumule, bearing tetraspores. 4. Apex of a fertile pin- 
nule. 5. A plumule bearing a favella. 6. Joint of a main branch or of 
the stem :—all magnified. 
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