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P late C L X V I I .
POLYSIPHONIA LRCEOLATA, Grev.
Gen. Ch a k. Frond filamentous, partially or generally articulate; joints
longitndinally striate, composed of numerous radiating cells or tubes,
disposed round a central cavity. Fructification two-fold, 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 olysiphonia (Grev.),— mXvs, many,
and a-idxov, a tube.
P o ly s ip h o n i a urceolata ; filaments rigid, setaceous, full-red, much branched,
loosely bundled ; branches dichotomous, more or less furnished with
short, alternate, patent or recurved ramuli ; articulations marked with
two broad tubes, those of the main branches 3 -5 times longer than
broad ; siphons four, surrounding a minute cavity ; capsules pitchershaped,
with a produced mouth, generally stalked ; tetraspores in the
upper part of the ramuli.
P o l y s i p h o n i a urceolata, Grm. FI. Fdin. p. 309. I la r v . in Hooh. Br. FI.
vol. ii. p. 330. Wyatt, Alg. Banm. no. 133, Harv. in Mack. I t . Hih.
part 3. p. 207. Harv. Man. p. 95. Fndl. 3rd Suppl. p. 45.
P o l y s ip h o n ia patens, Harv. in Hook. Br. FI. vol. ii. p. 330. Fndl. 3rd
Suppl. p. 54.
H utch in s ia urceolata. Hook. FI. Scot. vol. ii. p. 88. lyngh. Hyd. Ban.
p. 110. t. 34. A g .S y s t.- ÿ .\6 \. Ag. Sp. A f . l o l . i i . -ÿ. 19.
H utch in s ia patens. Ag. Sp. Alg. p. 71.
CoNPBEVA urceolata, Billw. no. 156. t. G. E. Bot. t. 3365.
Conferva patens, Billw. no, 157. t. G.
H ab . On rooks near low-water mark, and on the stems of Laminaria
digitaia. Annual Summer. Common on the shores of the British
Islands.
G e o g e . D i s t e . Atlantic shores of Northern Eui’ope. Iceland. North America,
D e sc r. Fronds densely tufted, often entangled at base, and connected by rootlike
fibres, from three to nine inches long, as thick as horsehair at base,
gradually attenuated upwards, much and irregularly branched, often very
bushy. Main branches somewhat dichotomous, more or less furnished with
short, lateral, simple, or sparingly divided patent ramuli, which bear- a few
thorn-like, lesser divisions. Sometimes these thorn-like ramelli are very
abundant, and hooked backwards, when the plant becomes P. patens of
authors ; at other times they are few and more erect. Articulations very
different in different parts of the frond : those of the lovyer' part of the
stem about as long as broad ; of the branches generally thrice, but sometimes
five times as long ; and of the ramuli, rather shorter than their
breadth ; all marked by two wide tubes, and exhibiting, when cut transversely,
four siphons surrounding a minute cavity. Capsules on short stalks,
ii