P l a t e CCCIII.
POLYSIPHONIA AFFINIS, Moore.
r . Keeve, im.p .
G e n . Ch a r . Frond filamentous, partially or generally articulate ; articulations
longitudinally striate, composed of numerous, radiating cells or
tubes, disposed round a central cavity. Fructification twofold, on
different individuals : 1, ovate capsules {ceramidia) furnished with a
terminal pore and containing a tuft of pear-shaped spores ; 2, tetraspores
imbedded in swollen branchlets. P o lysiphonia {Grev.),—from
noKvs, many, and a-i(j>ap, a tube.
P o lysiphonia a fin is ; filaments robust, elongated, cartilaginous below,
flaccid above, irregularly divided; branches patent, naked at base,
multifld and with an ovate outline above; ramuli very erect, simple
or divided, acute; articulations multistriate, the lower two or three
times longer, the upper as long as broad; siphons about sixteen;
ceramidia ovate, stalked or subsessile.
P olysiphonia affinis, Moore in Ord. Surv. Londonderry, Appendix, p. 11.
t. 7. Harv.Man.eA .2.p.90.
H a b . On rocks, &c., in the sea, thrown up from deep water. Carnlough,
near Glenarm, B r . Brummond. Cushendall, M r. Moore. (W .H .H .,
1 8 5 0 .)
Geogr . D ist r . ?
De sc r . Root a small disc. Fronds as thick as hog’s bristle a t base, attenuated
upwards, six or eight inches long or more, divided irregularly, or subdicho-
tomously into a few principal branches, or alternately branched ; branches
long, spreading, bare of ramuli in th e lowest part, more or less copiously
furnished with short branches above ; these lesser branches are one or two
inches long, with a broadly ovate outline, naked below, mnltifid above, the
lesser divisions repeatedly pinnate, all the divisions alternate. The tendency
to branch only at the upper portion of each rachis is equally characteristic
of the ultimate divisions as of the primary and secondary. Articulations
of the stem and branches twice or thrice as long as broad ; of the ramuli
shorter, with pellucid dissepiments ; siphons about sixteen. Capsules ovate
or subglobose, on short stalks or subsessile. Tetraspores large, in the ultimate
ramuli, which are then distorted. Colour varying from a pale to a
dark reddish-brown. Substance of the stem cartilaginous, of the upper
portion flaccid, and closely adhering to paper.
Very closely related to P. nigrescens, from which it chiefly