Ser. RHoposPpERME®. Pam. Rhodomelee. 
Pruatze CLXVII. 
POLYSIPHONIA URCEOLATA, Grev. 
Gen. Cuar. Frond filamentous, partially or generally articulate; joints 
longitudinally striate, composed of numerous radiating cells or tubes, 
disposed round a central cavity. ructification two-fold, on different 
individuals ; 1, ovate capsules (ceramidia), furnished with a terminal 
pore, and containing a tuft of pear-shaped spores; 2, ¢etraspores, 
imbedded in swollen branchlets. PotystpHonta (Grev.),—7odus, many, 
and oper, a tube. 
PorysrPHonta wrceo/ata ; 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 pitcher- 
shaped, with a produced mouth, generally stalked; tetraspores in the 
upper part of the ramuli. 
PoLysIPHONIA urceolata, Grev. Fl. Edin. p. 309. Harv. in Hook. Br. Fl. 
vol. i. p. 330. Wyatt, Alg. Danm. no. 133. Harv. in Mack. Fl. Hib. 
part 3. p. 207. Harv. Man. p.95. Endl. 3rd Suppl. p. 45. 
PotysipHonta patens, Harv. in Hook. Br. Fl. vol.ii. p. 330. Endl. 3rd 
Suppl. p. 54. 
Hurcuinsia urceolata, Hook. Fl. Scot. vol. u. p. 88. Lyngb. Hyd. Dan. 
p- 110. t.34. 4g. Syst. p. 151. Ag. Sp. Alg. vol. ii. p. 70. 
Hurcuinsta patens, 4g. Sp. Alg. p. 71. 
ConFEerRVA urceolata, Dillw. no.156.t.G. £. Bot. t. 2365. 
ConFERVA patens, Dillw. no. 157, t. G. 
Has. On rocks near low-water mark, and on the stems of Laminaria 
digitata. Annual Summer. Common on the shores of the British 
Islands. 
Geogr. Distr. Atlantic shores of Northern Europe. Iceland. North America. 
Descr. Fronds densely tufted, often entangled at base, and connected by root- 
like 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 lower part of the 
stem about as long as broad; of the branches generally thrice, but some- 
times five times as long; and of the ramuli, rather shorter than their 
breadth ; all marked by two wide tubes, and exhibiting, when cut trans- 
versely, four siphons surrounding a minute cavity. Capsules on short stalks, 
VOL. II. M 
