Ser. RHoposPERME. Fam. Spherococcoidee. 
Puate XXXII. 
RHODYMENIA BIFIDA, Grev. 
Gen. Cuar. Frond flat, membranaceous, or subcoriaceous, ribless, veinless, 
cellular; central cells of small size; those of the surface minute. 
Fructification of two kinds, on distinct individuals; 1, convex tuber- 
cles (coccidia) having a thick, cellular pericarp, and containing a 
mass of minute spores on a central placenta; 2, fetraspores imbedded 
in the cells of the surface, scattered, or forming cloudy patches. 
Ruopymenta * (Grev.)—from podeos, red, and ipyy, a membrane. 
Ruopymenta Zifida; frond thin and transparent, rose-red, dichotomously 
divided from the base; segments linear, or cuneate; apices obtuse ; 
tubercles mostly marginal, sessile ; tetraspores transversely zoned. 
Ruopomenta bifida, Grev. Aly. Brit. p. 85. Hook. Br. Fl. vol.ii. p. 289. 
Wyatt. Alg. Danm. no. 66. Harv. in Mack. Fl. Hib. part 3. p. 194. Hare. 
Man. p.60. Endl. 3rd Suppl. p. 51. 
DeeEsserta bifida, Lamour. Ess. p. 37. 
Spu#rococcus bifidus, 4y. Sp. Alg. vol.i. p. 299. Syst. p.231. Kiitz. Phyc. 
Gen. p. 410. 
Fucus bifidus, Goodw. et Woodw. Lin. Trans. vol. iii. p. 159. t.17.f.1. Sm. 
E. Bot. t. 773. Turn. Syn. p. 165: Turn. Hist. t. 154. 
Var. 8, ciliata; frond somewhat thicker than usual, opake, brownish red, 
narrow, much divided; the margins fringed with leafy cilia. 
Fucus bifidus, 8. ciliatus, Turn. Syn. p. 165. Hist. 1. e. 
Var. y, éacrassata ; frond thicker than usual, shrinking and changing to 
brownish red in drying, broad; segments cuneate, proliferous or 
ciliate at the margin. 
Has. On rocks in the sea, beyond the influence of the tide, and on Alge. 
‘Annual. Summer. Frequent on the southern shores of England ; 
and along the west, and south, and eastern coasts of Ireland. Yar- 
mouth, Mr. Wigg. Tynemouth, Mr. Winch. Belfast Bay, Mr. Tem- 
pleton. Jersey, Miss White. Ardrossan, Saltcoats, and Kilbride, 
Rev. D. Landsborough. Nar. y, Belfast Bay, Mr. W. Thompson. 
Carrickfergus, Mr. We’ Calla. 
Grocer. Distr. Atlantic shores of Europe. Mediterranean sea. 
Descr. Root discoid, accompanied by fibres. Fronds 1-2 or 4 inches high, 
growing in globose tufts, veinless, thin, delicately membranaceous, dicho- 
tomous with more or less regularity, usually much divided; segments 
* Spelled Rhodomenia by Dr. Greville ; altered to Rhodymenia by M. Montagne, 
as being more in conformity with the Greek. 
ia 
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