The ramification of Scytonema cirrkosum appears to differ from
that of S. myochrous, many threads springing from a single
sheath, as in the genus Microcoleus; and I am inclined to
think that it is essentially the same with that of Sirosipkon,
the outer tube being so tough that the branchlets do not
penetrate it, but creep along between the mother-thread and
its tube.
The plant of Mr. Borrer and Mr. Ralfs from the Snowdon
lakes appears to be the same as (that of Capt. Carmichael.
It forms flexuous tufts of brown, very slender threads, proceeding
in fascicles from membranous suberect sheaths, and
containing a single row of sporangia, scarcely so long as broad.
We must refer for the description of Capt. Carmichael’s plant
to the English Flora, where it is given from that gentleman’s
manuscript, in the possession of Sir W. J. Hooker.
The specimens figured were gathered in July 1841. It is
possible that Mr. Hassall’s genus Arthronema may be well-
founded, but at present it is too imperfectly characterized to
be adopted.—M. J. B.
Fig. 1, magnified termination of one of the simple fasciculate
young branches; 2, older portions of the sheath with
contained branches ; 3, fascicle of older filaments (themselves
compound), from a drawing by the Rev. M. J. Berkeley.