172 CALLITHAMNION. 



sub-simple, articulated, each joint having two or four oppo- 

 site or quaternate, slender, erect, pinnated ramuli. Hook. 

 Br. Fl. ii. p. 339; Wijatt, Alg. Danm. No. 182; Harv. 

 Phyc. Brit. ^. clxiv. — B. pumilum ; much smaller, the ra- 

 rauli more dense, and joints shorter. Cal. jjumilum, Harv. 

 in Hook. Br. Fl. ii. p. 339. 



On mud-coveved rocl<s near low-water mark, rare. South of England 

 and South and West of Ireland. Coast of Down, Mr. W. Thompson. /3. at 

 Miltown Malbay. — -S7e?ns 1 or 2 inches high, irregularly divided into 

 a number of long, sub-simple branches, which sometimes bear a second or 

 third series; branches linear, jointed, each joint furnished with two oppo- 

 site or four cruciate, slender, pinnate or occasionally simple, erecto-patent 

 ramuli, from a quarter of a line to a line in length, crowded at the tips of 

 the branches, which, to the naked eye, have a peculiar thickened and 

 darkened appearance. Colour a brownish red. Substance flaccid. Tetras- 

 pores elliptical, dark red, seated on the shortened pinnules of the ramuli. 

 Favellce unknown. Having lately had an opportunity of studying this 

 species in its habitat at Torquay, and finding it to vary much in size, and 

 in the length and composition of the ramuli, I do not hesitate to reduce C. 

 pumilum to it as a variety. 



3. C. Jioccosttm, Fl. Dan. ; frond capillary, very flaccid, 

 remotely much branched ; branches alternate, erecto-patent, 

 articulated ; every joint producing a pair of opposite, simple, 

 subulate, erecto-patent, minute ramuli ; tetraspores elliptical, 

 pedicellate, produced on the ramuli, near their base. Harv. 

 Phyc. Brit. t. Ixxxi. Cal. Pollexfenii, Harv. in An. Nat. 

 Hist. vol. xiv. p. 186, t. v./ 5— 7. Conferva Jloccosa, Fl. 

 Dan. t. 828. 



On submarine rocks, near low-water mark. Annual. Spring. Very 

 rare. Orkney Islands, Rev. J. H. PoUexfen. Aberdeen, Dr. Dickie.— - 

 Densely tufted, 1—5 inches long, very slender and flaccid, irregularly di- 

 vided into several principal branches, somewhat dichotomous ; branches 

 naked, or furnished at intervals with short, multifid lesser branches, having 

 an obovate outline; all the branching alternate. Every articulation of 

 stem and branches bears a pair of slender, and very short, opposite ramuli. 

 On these ramuli, toward their base the pedicellated tetraspores are borne. 

 Colour a bright purplish lake. A most beautiful and distinctly charac- 

 terised plant, of very rare occurrence, and seemingly confined to the nor- 

 thern parts of Britain. 



4. C. Tiirneri, Dillvv. ; stems rising from creeping fila- 

 ments, erect, simple or slightly branched, pinnated with 

 opposite, spreading, simple ramuli ; articulations of the stem 

 5—10 times longer than broad; tetraspores clustered, subra- 

 cemose or corymbose ; favellae involucrated, stalked. Harv. 

 in Hook. Br. Fl. n. p. 339; Wyatt, Alg. Danm. No. 183; 

 Harv. Phyc. Brit. t. clxxix. Conf. Turneri, E. Bot. t. 2389, 



