Ser. RHoposPpERME. Fam. Rhodomelee. 
Prate CCLXXVIII. 
POLYSIPHONIA SIMULANS, Zarv. 
Gun. Car. Frond filamentous, partially or generally articulate; joints 
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, ¢etraspores 
imbedded im swollen branchlets. Potystpnonta (Gev.), — from 
modus, many, and oar, a tube. 
PotystpHonta simulans ; filaments slender, bushy, branched from the base; 
branches alternate, patent, repeatedly (but irregularly) pimnate; the 
penultimate branches long and simple, set with short, distant, spine- 
like ramuli; articulations of the branches once and half as long as 
broad, of the ramuli shorter, many-tubed; siphons about twelve ; 
ceramidia globose or ovate. 
PoLysreHoNIA simulans, Harv. Man. ed. 2. p. 89. 
PoLysIPHONIA spinulosa, Griff. in Harv. Man. ed. 1. p. 87. (not of Grev.) 
PotysrpHonta divergens, y Grevilleana, Kiitz. Sp. Aly. p. 822. (Torquay 
specimens. ) 
Has. On rocks, &c., in tide-pools near low-water mark. Annual? 
Summer. Rare. Bathing Cove, Torquay and Torabbey Rocks, J/rs. 
Griffiths. Bovisand, Rev. W. 8. Hore. Jersey, Miss White and 
Miss Turner. Valentia, Kerry, W. H. H.  Skaill, Orkney, Rev. 
J. H. Pollexfen. 
Geoer. Distr. Not noticed out of Britain. 
Descr. Fronds densely tufted, two or three inches high, branched from the base 
and bushy, setaceous below, capillary above, irregularly divided. Branches 
alternate, somewhat pinnate, not perfectly distichous, decompound, the 
divisions set with short, subulate, scattered, spine-like ramuli, and con- 
nected together by irregular spine-like processes, so that the lesser divisions 
are difficult to spread out. Articulations of the stem and branches about 
once and half as long as broad, of the ramuli very short, with pellucid dis- 
sepiments, multistriate ; siphons about twelve, surrounding a small central 
tube. Ceramidia ovate, sessile, scattered on the smaller branches. Te¢ra- 
spores immersed in slightly swollen ramuli. Colour a dull reddish-brown, 
or dark brown-red. Sudstance stiff and brittle, becoming flaccid in fresh 
water, and then adhering to paper. 
ee 
In the first edition of my “ Manual,” I fell into an error in 
confounding this species with P. syinulosa of Greville, a plant to 
