330 ALG.E CONFERVOIDE/E. [Polysiphonia. 



On sand-covered rocks, not uncommon on any of our shores. — 

 Root "a network of perennial creeping filaments," (Carm.), 2—10 

 inches high, forming densely entangled tufts of a dull red or purplish 

 colour. Capsules and granules abundantly produced. 



7. P. urceoldta, Grev. (pitcher -fruited Polysiphonia) ; filaments 

 rigid cartilaginous much branched loosely entangled, branches 

 dichotomous erecto-patent, middle articulations 4 — 5 times longer 

 than broad, capsules urceolate shortly pedunculate. — Conferva 

 urceolata, Lightf MSS.— Dillw. Conf t. G.—E. Dot. t. 2365. 



On rocks and the larger Algae, not uncommon. — 3 — 9 inches high, 

 dark-red, as thick as horse-hair at the base, loosely entangled in large 

 bundles, of nearly equal diameter throughout. Articulations very vari- 

 able, the lowest 5—6, middle 4 — 5 times longer than broad, the ultimate 

 ones very short: dissepiments broad and hyaline. Substance rigid, and 

 scarcely adhering to paper. — Such is the usual state of this plant; but 

 Dr. Greville finds a variety (if it be only a variety) at the Isle of Bute, 

 in which the filaments are scarcely a third of their usual diameter, ex- 

 cessively branched and adhering most closely to paper. 



8. P. patens, Grev. (patent Polysiphonia); filaments cartila- 

 ginous sparingly branched entangled beset with short patent re- 

 curved ramuli bi-striate, middle articulations 2 — 3 times longer 

 than broad, capsules urceolate subsessile. — Hutchinsia patens, 

 Ag. Sp. Alg.v. 2. p. 71. — H. urceolata, Lyngb. Hydroph. Dan. 

 t. 34— Conf. patens, ? ? Dillw. Syn. Conf. p. 83. t. G. 



On the stems of Laminaria digitata, common. — 3 — 8 inches high, 

 thicker than horse-hair, loosely matted, dull red. Stems sparingly di- 

 vided, but beset throughout their whole length with short patent 

 branches ; these are, again, more or less thickly furnished with short, 

 remarkably recurved and squarrose ramuli, which constitute the most 

 striking characteristic of the species : if indeed it be really distinct from 

 P. urceolata. Whether this be the Conf. patens of Dillwyn or not, I 

 am unable to determine, the only specimen of that species which I have 

 seen, being in a very young and imperfect state, and I am not aware that 

 it was ever found in fruit. 



* * Filaments poly striate. 

 \ Rigid ; strice 3, ramuli spiniform. 



9. P. spinulosa, Grev. (spinous Polysiphonia); " dark red, 

 branches divaricate somewhat rigid, the ramuli short straight 

 subulate divaricate, articulations about equal in length and 

 breadth, three-tubed." Grev. Crypt. Fl. t. 90.— Hutchinsia 

 spinulosa, Ag. Sp. Alg. v. 2. p. 75. 



Sea-shores, extremely rare. Appin, Capt. Curmichael, who only found 

 one specimen. 



10. P. parasitica, Grev. (parasitic Polysiphonia) ; rigid, 

 branches distichous bi-tripinnate, pinnulse alternate erect spini- 

 form, articulations as long as broad three-tubed. — Conferva 

 jxirasitica, Huds.—E.Bot.t. 1429. Dillw. Conf. Syn. p. 87 — 



