CALLITHAMNION. 183 



Hnrv.in Hook. Br. Fl. ii. p. 347; Harv. Phyc. Brit. t. ccxii. ; 

 Wyatt, Alg. Danm. No. 94. Conf. pedicellata, E. Bat. t. 

 1817. 



On rocks, &c. near low-water mark, not uncommon. Summer. — Fila- 

 ments 2 — 8 inches high, rather flaccid, as thick as horse-hair , branches lonsf, 

 and little or much divided, springing from near the base, beset with short, 

 dichotomous ramuli, which are often crowded at the tips, so as to give the 

 plant a pencilled appearance; apices always rounded and obtuse. Articu- 

 lations extremely variable in length in different specimens, in some four, 

 in others twelve times longer than broad. Colour a fine red, which is ra- 

 pidly given out in fresh water, and becomes in the herbarium a dull dingy 

 brown. Tetraspores elliptical or pear-shaped, very dark, raised on little 

 colourless stalks situated in the axils of the branches. PavellcB large, sin- 

 gle or in pairs, on the stems. 



Section 5. Pulvinata. Filaments short, densely tufted, 

 forming cushion-like tufts, or spreading in velvetty 

 patches. (Sp. 27—29). 



27. C. Rothii, L. ; widely spreading, densely tufted; fila- 

 ments slender, .short, erect, dichotomous ; branches long, 

 straight, apprcssed ; articulations twice as long as broad ; 

 tetraspores chistered, borne on short, terminal, sub-corym- 

 bose ramuli. Harv. in Hook. Br. Fl. ii. p. 347 ; Harv. Phyc. 

 Brit. t. cxx. B ; Wyatt, Alg. Damn. No. 188. Conf. 

 Rotliii, E. Bot. t. 1702, — /3. purpureum ; filaments very mi- 

 nute, forming continuous velvetty patches, slightly branched. 

 Cal. purpureum, Harv. Man. Vsi ed. \, p. 116. Byssus pur- 

 purea, E. Bot. t. 1 92. 



On marine rocks, above half-tide level. Perennial. Fruiting in winter. 

 — Filaments a quarter of an inch to nearly an inch in height, forming 

 large velveity patches, of a deep red or purple colour. Branches few and 

 very erect, either dichotomous or alternate, equal. Fructification, as first 

 pointed out by the late Capt. Carmichael, frequently produced in the win- 

 ter mouths. 



28, C. Jloridulum, Dillw. ; filaments short ; densely tuft- 

 ed, fastigiate, sparingly branched ; branches alternate or 

 sub-dichotomous, nearly simple, appressed ; articulations 

 thrice as long as broad ; tetraspores minute, oval, borne on 

 very short, closely appressed pedicels, ranged in a secund 

 manner along the upper branches. Harv. I. c. p. 348 ; Harv. 

 Phyc. Brit. t. cxx. A. Conf.Jloridula, Dillw. Suppl. t. F; 

 Wyatt, Alg. Danm. No. 219. 



On marine rocks, near low-water mark. West of Ireland, extremely 

 common. Orkney, Dr. PoUexfen. Land's End, Mr. Rulfs. — Filaments 



