132 
ECTOCARPACEiZE. 
IV. 
venture to introduce it into tliis work, though I have not received it from any 
correspondent in America. 
Myrionema strangulans , Grev. ; patches convex, confluent, brown ; vertical fila- 
ments clavate, densely set ; spores obovoid, on short stalks, attached to the decum- 
bent filaments. Grev. Crypt. FI. t. 300. Harv. Phyc. Frit. t. 280. J. Ay. Sp. 
Alg. 1, p. 48. Kiitz. Sp. Alg. p. 540. 
Hab. Parasitical on the fronds of TJlvce and Enter omorphce ; common on the 
shores of Europe, (v. v.) 
This parasite first appears like a dark brown stain, spotting the plant on which 
it grows, and at this stage consists of little more than an imperfect membranous 
expansion, composed of prostrate filaments. Afterwards, by the growth of the 
erect filaments, the spots become convex and gelatinous, and the plant is matured. 
The spores are of large size (for the plant), and arise, like the vertical filaments, 
from the upper face of the decumbent ones. 
M. Leclancherii , and M. punctiforme are, with the preceding, probably to be found 
on the American shores. 
Order YI. ECTOCABPACEiE. 
Ectocarpeae, C. Ag. Sp. Alg. vol. 2, p. 9- (excl. gen.) Harv. Man. Ed. 1, p. 38. 
Ed. 2 ,y>. 52. Kiitz. Sp. Alg. p. 449- Ectocarpe^: and Sphacelarieae, J. Ag. Alg. 
Medit. p. 26. Sp. Alg. vol. 1, p. 6, 27. Ene. Ess. p. 33, 42. Kiitz. Phyc. Gen. p. 
287, 291. Ectocarpedas, (in part) and Sphacel ariose, Lindl. Veg. Kingd. p. 22. 
Diagnosis. Olive-coloured, articulated, filiform seaweeds, whose spores are 
(generally) external, attached to the jointed ramuli, or formed in a swelling of the 
ram ulus. 
Natural Character. Boot commonly a small disc, or point of attachment, 
occasionally accompanied by woolly fibres. Frond filiform and slender, (or fila- 
mentous ) often capillary, or of extreme tenuity, more or less conspicuously articu- 
lated, each articulation composed either of several cells of equal length disposed 
in a ring round an axis, or of a single cell. In the latter case the frond is said to 
be a filament ( filum , Ag. trichoma , Kg.) and is formed of a series of cells, placed 
end to end, and strung together. In some of the higher forms, as in Cladostephus 
and Choetopteris , the main stem and the larger branches are inarticulate, formed of 
