land. The similarity is indeed so striking, that I do not believe
a doubt could exist in the mind of any one who saw them
together, of their being individuals of the same genus.
I have adopted A g a r d h ’s character of the genus Ulva,
but it seems to me as if it wanted revision. In short, we require
to know a little more regarding the reproduction of some of these
plants; and till this point can be satisfactorily decided, the
fructification should be rather avoided in the character. Are
the granules, which, in fact, give the dark green colour to the
frond, to be considered seeds ? This is very doubtful, indeed;
and yet we have an easy transition to Chlorococcum vulgare,
where granules apparently similar form the entire plant, and
must necessarily contain the fructification. The fructification
of Bangia mlophylla and Scytosyphon velutinus, is equally
unknown.
Fig. 1. Ulva furfuracea, natural size. Fig. 2. A tuft of fronds. Fig. 3. Separate
fronds. Figs. 4, 5, 6. Portions o f fronds exhibiting different arrangements
of the gramdes, magnified.
A .