Plate XVIII. 
Fig. 75. MYRIONEMA CLAVATUM. 
Colour. Nearly the colour/’ says Captain Carmichael, “ of the then purplish crust on which 
it grows.” 
Character of Frond. ‘‘Very minute; rather convex,” the threads {filaments) of which it is 
composed, club-like (“ clavate^') ; mostly cleft in two (“ hifid'^). 
Measurement. The description does not specify. 
Fructification. Minute seeds (spores) affixed to the filaments. 
Habitat. Not defined. 
Nothing is known of this plant beyond Captain Carmichael’s description and figure, and 
the account is very imperfect. For the other Myrlonemas^ refer hack to Plate XVI. Figs. 
68 , 69 , 70 . 
Fig. 76. SPHACELARIA SERTULARIA. 
Colour, Olive-green. 
Substance. Rigid ; hut delicate. 
Character of Frond. Delicately bushy. Stem and branches jointed throughout; thread-like 
(filiform). Stem slightly shaggy at base ; weak and slender ; irregularly branched. 
Branches alternate ; spreading horizontally ; two or three times re-branched. Angles 
of branching very wide. 
Measurement. Scarcely 3 inches long. 
Fructification. Oval seeds (spores) borne on the branchlets. 
Habitat. From deep water. South of England, and North and West of Ireland. Very rare. 
A smaller and slenderer plant than S. filicina^ hut Dr. Harvey hesitates about making 
two species of them. 8. Jilicina has, however, all its angles of branching very acute and 
narrow; while those of 8. sertularia are very obtuse and Avide ; the branching of 8. filicina 
is therefore erect, that of 8. sertularia spreading. 
Fig. -77. SPHACELARIA CIRRHOSA. 
Colour. Dark- brown ; or rusty. 
Substance. Rigid ; yet not coarse. 
Character of Frond. A star-like tuft, more or less dense, growing on the stems of other 
alg£e. Jointed throughout ; thread-like (filiform) ; assuming many forms. Each 
thread {filament) of the tuft, branched with short, often (but not always) opposite 
branchlets. There are many deviations, and the branching is more or less com- 
plicated, but S. cirrhosa is always a tuft. 
Measurement. An inch or more long ; often less. 
Fructification. Globose seeds (spores) borne on the branchlets. 
Habitat. Our coasts everywhere. On Halidrys silicpiosa abundant ; and common on numerous 
other plants. 
A very dwarf variety has been observed by Miss Cutler, on the stems of Desmarestia 
aculeata. 
