lobed, witli a wide limbus, aud containing masses of dark-red, angular
spores. Tetraspores contained in splierical, pedicellate involucres composed
of a wborl of dicliotomous ramuli, borne along tbe sides of the brancbes.
Besides these normal kinds of fruit, what appeal's to be an abnoimal effort
at fructification (or possibly antheridia ?), is sometimes found; consisting of
oval bodies, composed of bundles of excessively fine dichotomous filaments,
contained in involucres similar to those occupied by tetraspores, and attached
in the same manner as tetraspores ai-e (fig. 7, 8, 9.). Colour when fresh,
a dark full red, becoming brownish in dryuig. Substance firm, and somewhat
cartilaginous.
Griffitlma equisetifolia was first described by Ligbtfoot in the
year 1777, in his ‘Llora Scotica’, on the authority of a specimen
communicated by Mr. Yalden from the Lrith of Lorth, and it is
not a little remarkable that though the plant has been found on
most parts of the Lnglish and Irish coasts, since Lightfoot’s
time, yet no more recent instance of its occurrence in Scotland
has been recorded, nor have I received it from any of my Scotch
correspondents.
While in fructification it perfectly agrees with others of the
genus; it diifers considerably in habit from all, with the exception
of G. simplicifilum, a plant which ought, perhaps, rather to be
considered as a slender variety of the present, than as a distinct
species.
The curious bodies which I have noticed in the description
under the name of antheridia, and introduced into the plate,
were communicated to me by Mrs. Griffiths, who discovered
them last year, on some specimens collected many years ago at
Torquay. They are of a very anomalous nature, which in the
present state of our knowledge it is impossible to explain. Similar
bodies are frequently produced by G. setacea, on which they were
first noticed by Miss Biddulph; and are found on so many species
of Callithamnion, that one is tempted to anticipate their
being detected upon all. Should this prove to be the case, it
will certainly favour the idea of their analogy with antheridia,
and discredit the notion which I have hitherto entertained,
namely, that they are a viviparous state of tetraspores.
Fig. 1. Ge if f it h s i.a euuisetifolia :—the natural size. 3. Portion of a branch,
and two involucres. 3. A ramulus. 4. An involucre. 5. A tetraspore. 6.
Apex of a branch, with a favella. 7. Involucre producing antheridial.
8. Mi antheridiumt 9. Fragment of the same:—all more or less J
magnifed.
J.