Rhodomenm.] ALG.E INARTICULATE. 289 



— Name; go2o:, red, and vpw, a membrane. — This seems to differ 

 from some of the Nitophylla, solely in the ternate granules being 

 scattered over the whole surface of the frond, not collected into 

 definite spots. 



1. R. bifida, Grev. (bifid Rhodomenia); frond thin membran- 

 aceous dichotomously divided broadly linear, the segments often 

 subcuneate obtuse, capsules hemispherical chiefly marginal. — 

 Grev. Alg.Brit.p. 85. — Delesseria bifida, Lam our-. — Sphcerococcus 

 bifidus, Ag. Sp. Alg. v. 1. p. 299. — Hahjmenia bifida, Gmel. — 

 Fucus bifidus, Good, et Wood iv. in Linn. Trans, v. 3. t. 17. f. 1. 



E. Bot. t. 773. Turn. Syn. Fuc. p. 163, Hist. Fuc. t. 15-J 



/3. ciliata; frond somewhat cartilaginous purplish-brown opaque 

 divided, the margins fringed with spathulate laciniae. Turn. I. c. 

 On rocks and the larger sea-weeds, not unfrequent on the coast of the 

 south of England, especially of Devonshire and Cornwall. Norfolk and 

 Suffolk. Tynemouth. Belfast and Bantry, Ireland: ©.Summer. — The 

 more usual state of this plant is of a beautiful deep rose-red, the margins 

 free from laciniae or nearly so ; but the ciliated variety is so beset with 

 linear, or, more frequently, spathulate laciniae, and is so copiously divided, 

 that it can hardly be recognised as the same species ; its colour is much 

 less bright, and its texture thicker and more opaque. From Mrs. 

 Griffiths I possess numerous specimens. In some of these the capsules 

 are by no means confined to the margin. The scattered granules are 

 principally in the extremities of the frond, often, however, extending a 

 good way down : frequently in the marginal laciniae. The spreading 

 fronds are from one to three inches in length. 



2. R. lacinidta, Grev. (Jaciniated Rhodomenia); frond sub- 

 cartilaginous palmatedly dichotomous, the segments broadly 

 linear-oblong obtuse or erose often fringed with marginal la- 

 cinia? (linear or lanceolate) in which the sphaerical capsules are 

 situated, scattered granules marginal. — Grev. Alg. Brit, p. 86. 

 — Delesseria laciniata, Grev, Fl. Edin. — Hook, in 11. Loud. X. 

 Sir. cum Ic. — Fucus laciniatus, Buds. — Turn. Syn. Fuc. p. 161, 

 Hist. Fuc t. (19. E. Bot. t. 1068. 



More or less abundant upon all the coasts of Great Britain: \<i\ 

 rare near Edinburgh, according to Dr. Greville. $ . Fructification 

 Spring and Summer. — 4— G or S inches long. The smaller and more 

 delicate specimens have much resemblance to R. bifida. 



3. R. polycdrpa, Grev. (many-fruited Rhodomenia); frond 



between cartilaginous and membranaceous dichotomous or some- 

 what palmate, the segments Bublinear laciniated and acute at the 

 ends, capsules hemispherical scattered over the frond. Grev, 

 Alg. Brit, p. 87, and Spharococem polyc.y Gn v. ( rypt II. t. 852, 

 Cast on shore under Tail's Hill, near Plymouth, 1814 ; Miss Hii/» 

 Whitsand Bay, Mr, Arnott. £.?— • Frond seven inches in length. Of 

 this the capsular fructification only is known " Its structure i> d. 

 and vcrv similar under the microscope to that of Rhodon tkt§ 



but the different colour (opaque, dull, pink- red, ?erj dark at the b 



V 



