taken from one of Miss Warren’s specimens, and it appears to 
be identical with what I have received from M. Lenormand as 
the Halymenia Dubyi of Chauvin. It will be seen that the 
frond is considerably different in form from the typical spe- 
cimens of A’. rexiformis, the outline much more approaching 
that of Jridea edulis. Some of Miss Warren’s specimens are 
even larger than here represented; but the majority are of less 
size. All have very much the same general outline: those 
gathered at a later period of the year are of a much firmer con- 
sistence and denser substance than the rest. From the Rev. Mr. 
Hore I possess specimens gathered at Plymouth, quite similar to 
the Falmouth ones, except that they are split at the apex; a 
peculiarity which originated, Mr. Hore informs me, after they 
had been gathered. Iam not quite so certain that the Irish 
habitats given, on Mr. Thompson’s authority, belong to this 
species, and not to a variety of K. reniformis, the specimens 
which I have seen not being in a sufficiently perfect state to 
remove all ambiguity. Should these stations be established, the 
merit of having added a new plant to our flora must attach to 
Miss Davison; whose specimens are dated so long back as 1833. 
Besides mere form, which is not absolutely to be depended 
on, this plant differs from K. reniformis in the duller colour, 
in its globules of spores being of a much smaller size, and some- 
‘what in the structure of the frond. It arrives at maturity, too, 
at a much earlier season, being in greatest perfection in March 
and April, and becomimg much faded and passing into decay ia 
August; just at the period when the full-grown and strongly 
coloured fronds of Kal. reniformis beg to come on shore. 
Whether or not that species be perennial, as seems probable, 
from the proliferous individuals which are frequently found, the 
present is certainly an annual, arriving at maturity and passing 
away within six months. 
Fig. 1. Katnymenia Dusyt:—of the natural size. 2. Transverse section of 
the frond, and of the favellidia. 3. Fragment, to show the surface cellules. 
4. A favellidium :—magnified. 
