lobed, with a wide limbus, and containing masses of dark-red, angular 
spores. Tetraspores contained in spherical, pedicellate involucres composed 
of a whorl of dichotomous ramuli, borne along the sides of the branches. 
Besides these normal kinds of fruit, what appears to be an abnormal 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 are (fig. 7, 8,9.). Colour when fresh, 
a dark full red, becoming brownish in drying. Substance firm, and somewhat 
cartilaginous. 
OPO ae 
Grifithsia equisetifolia was first described by Lightfoot in the 
year 1777, in his ‘ Flora Scotica’, on the authority of a specimen 
communicated by Mr. Yalden from the Frith of Forth, and it is 
not a little remarkable that though the plant has been found on 
most parts of the English and Irish coasts, since Lightfoot’s 
time, yet no more recent imstance 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 differs 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, se¢acea, on which they were 
first’ noticed by Miss Biddulph ; and are found on so many spe- 
cies 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. GRIFFITHSIA EQUISETIFOLIA :—the natural size. 2. Portion of a branch, 
and two involucres. 3. Aramulus. 4. Aninvolucre. 5. A tetraspore. 6. 
Apex of a branch, with a favella. 7. Involucre producing antheridia?. 
8. An antheridium? 9. Fragment of the same :—all more or less highly 
magnified. 
