eye, a crustaeeous Liehen, than an Alga, but its straeture and
fraetifieation prove it to be widely different from any Lichen.
There is a curiously close resemblance, both in the habit, the
structure of the frond, and the outward character of its fruit,
between Balfsia and Beysonellia; yet, according to the received
notions of arrangement, these plants must be referred to opposite
parts of the system. They are, however, closely analogical forms,
in the families to which they respectively belong. Lxcept for
the colour, and the different formation of the spores, there
would be little to distinguished them.
Balfsia deusta is a very common species throughout the
Northern Atlantic Ocean, and probably extends along most of
the shores of Emope, North Asia, and North America; though
not yet recorded from the latter. Its crustaceous habit may
often cause it to be over-looked.
Endlicher has confounded it with the very different Hilden-
hrandtia rubra (which is also common on the British coast); and
Areschoug has, still more unhappily, put it into the same genus
as Cruoria pellita, with which, in structure, it has very little
connection. The resemblance between these is purely external.
The fructification of Balfsia is either very rarely produced, or
so difficult to find, owing to its obscurity, that it is rarely seen.
It was first observed, I believe, by Dr. Johnston, who communicated
the specimens to Mr. Berkeley, by whom they were described.
Though myself familiar with this plant for many years,
I had never seen the fruit, until I received fertile specimens from
Dr. Dickie of Aberdeen, and from these I have made my analysis.
On the west coast of Scotland and of Ireland this plant is excessively
abundant, and its patches reach a large size. Devonshire
specimens, communicated by the Bev. Mr. Cresswell, are much
inferior.
K g . 1. E alfsia deusta, young aud old fronds :— o f ike natural size. 2, Vertical
section of the frond. 3. Füaments of wMch the frond is composed.
4. Spores, among the filaments of a wart. 5. A spore and its filaments,
sepai-ated :— all more or U