Ser. RHoDOSPERMEZ. Fam. Gloiocladhee. 
Puate CCXLIV. 
DUDRESNAIA COCCINEA, Bozzem. 
| Gen. Cuar. Frond cylindrical, gelatinous, elastic; aris composed of a lax 
| net-work of anastomosing filaments, coated with a stratum of closely 
| combined, longitudinal fibres; the periphery of horizontal, dichoto- 
| mous, moniliform filaments. Fructification, of two kinds, on different 
| individuals ; 1, globular masses of spores (favellidia) attached to the 
| filaments of the periphery. 2, external zoned ¢etraspores, borne on 
the filaments of the periphery, generally terminating a ramulus. 
Dupresnata (Bonnem.),—in honour of M. Dudresnay. 
Dopresnata coccinea; frond rosy red, tender and gelatinous, much and 
irregulary branched; branches alternate, flexuous, moniliform, atten- 
uated upwards; ramuli more or less numerous. 
DupREsNaIA coccinea, Bonnem. in Journ. Phys. vol. xciv. p.180. Crouan, 
Nouv. Ann. Sc. Nat. vol. iti. p. 98. t. 2. f.3-4. J. Ay. Alg. Medit. p. 84. 
Endl, 3rd Suppl. p. 37. 
MesoGtota coccinea, 4g. Syst. p.51. Hook. Br. Fl. vol. ii. p. 386. Wyatt, 
Alg. Damn. no. 148. Harv. in Mack. Fl. Hib. part 3, p.186. Harv. 
Man. p. 48. 
Rivvaria verticillata, H. Bot. t. 2466. 
Has. On rocks &c., near low-water mark; or, more generally, in 4-10 
fathom water. Annual. Summer. Very rare. Brighton, Mr. Borrer. 
Sidmouth and Torquay, Mrs. Griffiths and Miss Cutler. Salcombe, 
Mrs. Wyatt. Plymouth, Rev. W.8. Hore. Falmouth, Miss Warren. 
Jersey, Miss White and Miss Turner. Bantry Bay, Miss Hutchins. 
Grocer. Distr. Atlantic coasts of France. 
Desc. Root, a very small, conical disc. Fronds from six to ten inches high, 
much branched and bushy: sometimes with a single stem closely set with 
lateral branches, sometimes divided near the base into several stems. Stem 
or its divisions, set with alternate, patent branches, the lowest of which are 
longest, the upper gradually shorter. These bear a second and a third, 
and in luxuriant specimens a fourth series of smaller branches and ramuli ; 
each series being more and more slender, and the last about as thick as 
bristles. In some specimens the branches and ramuli are very dense, in 
others they are distant and bare. In the young frond the axis is a simple, 
articulated filament giving off at its joints whorls of dichotomous, moniliform 
ramuli; but as it advances in age the central filament or axis divides into 
several, or others grow round it, and the whorls are much more densely set. 
Thus in young plants the branches appear moniliform like those of a Batra- 
chospermum ; but in old plants they are cylindrical. Favellidia large, lodged 
at the base of dense, much divided ramuli. Tetraspores transversely four-~ 
c 2 
