F L a J o C C e m .
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w H .H . I e l rt I n k . E. B -e e v e .iiiïj.
P l a t e CCCVII.
RHODYMENIA CRISTATA, Grev.
G e n . Ch a e . Frond flat, membranaceous or subcoriaceous, ribless, veinless,
cellular; central cells of moderate size, those of the surface minute.
Fructification: 1, convex tubercles {coccidia), having a thick, cellular
pericarp, and containing a mass of minute spores; 3, tetraspores,
either zoned or tripartite, imbedded among the cells of the surface,
scattered, or forming cloudy patches. E hodymenia (Grew.),— from
poSeor, red, and ipgv, a
E hodymenia cristata; frond fan-shaped, membranaceous, subdichotomous,
the segments dilated upwards, repeatedly subdivided ; lesser divisions
alternate, linear, laciniate at the ends and often fimbriate at the
margin ; tubercles spherical, marginal, sessile..
E h o d y m e n i a cristata, Grev. Alg. Brit. p. 89. Hooh. Br. FI. vol. ü. p. 290.
Harv. Man. ed. 2. p. 126. Endl. 3rd. Suppl. p. 210.
Callophyllis cristata, Kütz. Sp. Alg. p. 747.
S p h /E R O C o c c u s cristatus, Ag. Syn. p. 29. Lyngh. Hyd. Dan. p. 13. t . 4 . Ag.
Sp Alg. vol. i. p. 300. Ag. Syst. p. 231. Hook. El. Scot. part 2. p. 104.
Grev. Crypt. Scot. t. 85. FI. Edin. p. 296. Kütz. Phyc. Gen. p. 410.
Fucus cristatus, Herb. lin n . Turn. Hist. t. 23.
Fucus gigartinus, FI. Dan. t. 394. Mohr, Hist. Isl. p. 247. Gunn. FI.
Norv. n. 847.
U ab Growing on the roots and stems of Laminaria in deep water, very
rare. Annual. July. Sea-shore at Wick, Caithness, Messrs. Hooker
and Borrer. Frith of Forth, Dr. Greville. Berwick, B r . Johnston.
Shetland, at Bressay, in fourteen fathoms. Pro f. E. Forbes. Several
stations in the Orkney Islands, in 8-10 fathoms, Lieut. Thomas and
B r. M 'B a in .
Geoge . D is t e . Arctic Sea, and shores of the North of Europe. Iceland.
Eastern shores of North America, as far south as Cape Cod.
Desc r . Boot minute, discoid. Fronds in British specimens from half an inch
to an inck, rarely two inches long, in American from two to four or five
inches, from one to three or four lines in breadth, fan-shaped or semicircular
in outline, sometimes quite fastigiate, sometimes irregularly divided,
some of the branches far out-topping the others, excessively branched from
the base. Branches linear, or slightly broader upwards, subdichotomous,
but very irregular in division; sometimes alternately divided, sometimes
secuiid, and sometimes fingered, or branched in a manner compounded of
all these. The lesser divisions arc usually bordered with slender, jagged