part of the frond also : tliese are rarely indistinct, and arc often very well
defined. The axils are patent, the apices spreading widely. A variety is
common in which the lateral smaller lobes of the froud hook backwards and
coil round any neighbouring plant. Coccidia depressed, spheroidal, generally
marginal or in marginal processes, containing, on a central placenta,
numerous chained spores. Spots of tetraspores minute, oblong, confined to
a line immediately within the margin, or else placed in little leafy processes
which fringe the principal laciniæ of the frond. Substance delicately membranaceous,
and very thin, but somewhat tough, elastic, and not adhering
strongly to paper. Colour a purplish or brownish full red, reflecting glaucous
tints when growing.
This is the most generally dispersed species of Nitophyllum, and
the one most usually met with within tide marks. It frequently
is found fringing the steep and shaded sides of deep rocky pools,
when protected from the sun by overhanging Fuci; but its
favourite place of growth seems to be on the stems of the larger
oai>weeds. The frond varies much in breadth in different
specimens, as may be seen by our figure, which, however, by no
means represents the extreme forms. Some specimens are so
broad and so little divided that they closely approach N. Gmelini
in aspect, especiaUy when dried ; but the substance and colour of
the two plants are essentially different, and when seen growing it
is impossible to mistake one for the other. A very singular
variety of N. laceratum is frequently seen between tidemarks,
attaching itself by hooked lobes to neighbouring small algæ, and
sometimes so intricately interwoven with their stems that it
cannot be extricated without tearing. In this the frond is very
narrow, of a brighter colour than usual, and almost every lobe
converted into a strong recurved hook.
I have frequently observed spores to be developed within the
substance of the placenta, as well as on its outer surface. Our
figure (fig. 4) represents them in both positions, as seen in a
vertical section of the conceptacle.
Fig. 1 . N it o p h y l l u m l a c e r a t u m ; a broad variety. 3 . A narrow variety,
with marginal processes ;—both of the natural size. 3 . SmaU portion of the
membrane with a marginal coccidium. 4. Section of the coccidium. 5.
Marginal spot of tetraspores. 6. Marginal processes containing spots of
tetraspores:— all magnified.