POLYSIPHONIA. 83 



On rocks, &c., between tide-marks. Annual. Summer. Not uncom- 

 mon. Filaments 6 10 inches high, exceedingly slender and flaccid, much 

 divided, with many long, slender, wavy branches, bearing a second or third 

 series, and ultimately a few irregular, spreading, or erect ramuli. Joints 

 of the main branches very long, those of the ramuli shorter, two-tubed. 

 Capsules sessile or shortly stalked ; tetraspores large, in the ramuli, often in 

 beaded strings. This species has many points in common with P. urceo- 

 lata, but is a much more slender and flaccid plant, and the capsules are 

 different. 



3. P. stricta, Dillw. ; filaments densely tufted, setaceous, 

 flaccid, bi-striated,dichotomous; branches and ramuli straight, 

 erect ; axils acute ; upper articulations 4 or 5 times longer 

 than broad ; 'capsules ovate, sessile. Hook. Br. Fl. ii. p. 

 329. Con/, stricta, Dillw. t. 40. 



In the sea, on sand-covered rocks. " Not uncommon ; " Dillw. Fila- 

 ments 2 10 inches high, rising from a mass of creeping fibres. Colour 

 dull red or purplish. A very ill-defined, confused species, which I do not 

 understand, nor can it be determined without a careful examination of the 

 original specimens, figured by Dillwyn. In herbaria we sometimes find 

 P.formosa, sometimes P.fibrala under this name. 



4. P. pulvinata, Ag. ; filaments rising from a mass of 

 creeping fibres, tufted and interwoven, short, very slender, 

 flexuous, sparingly and irregularly dichotomous, more or less 

 furnished with very patent or recurved, simple ramuli ; arti- 

 culations variable in length, bi-striated ; ceramidia pitcher- 

 shaped, very large, scattered. Harv. Phyc. Brit. t. cii. P. 

 macrocarpa, Harv. in Fl. Hib. iii. p. 296; Wyatt, Alg. 

 Danm. No. 215. 



On rocks and Algas between tide-marks. Annual. Summer. Not un- 

 common. Tufts dense, intricate, about an inch in height, composed of very 

 slender, capillary, flexuous filaments, variously branched. Colour a dull 

 brownish-red or purplish. Capsules very large for the size of the plant, 

 several times the diameter of the filament from which they spring. Sub- 

 stance soft and flaccid, soon decomposing in fresh water. 



5. P. Jibrata, Dillw. ; stems setaceous, flaccid, gelatinous, 

 simple or alternately branched, bearing at greater or less dis- 

 tances, dichotomously divided, more or less pencilled or 

 tufted ramuli, whose tips are fibrilliferous ; axils patent ; ar- 

 ticulations bi-striate, varying greatly in length ; ceramidia 

 ovate, generally stalked. Harv. Phyc. Brit. t. ccviii. ; Harv. 

 in Hook. Br. Fl. ii. p. 329 ; Wyatt, Alg. Danm. No. 39. 

 Conf. fibrata, Dillw. ! Conf. Syn. p. 84, t. G. 



On rocks, stones, and Algae, between tide-marks, not uncommon. An- 

 nual. Summer and Autumn. Stems 2 10 inches long, densely tufted, 

 dark red-brown, tender and gelatinous, decomposing rapidly in fresh water; 



G 2 



