Fig. 275. CALLITHAMNION THUYOIDEUM. 
Colour. A fine rose-red. 
Substance. Soft arid limp. 
Character of Frond. Tufts (or single plants) of very fine, jointed threads {filaments) ; very 
much branched. Stems exceedingly slender ; nearly simple below, set above with 
alternate branches. These once or twice re-branched. The lesser ones, and some- 
times all, clothed with branchlets, which are beautifully plumed and re-plumed with 
one, two, or even three sets of gradually-diminishing branchletee/is. The whole 
branching at one level, as if cut^ out. Outline of the plumed branches very narrow 
oblong. 
Joints, Visible throughout. 
Measurement. One or 2 inches long. 
Fructification. Of two kinds. 1. Minute spores in large oval capsules; generally sessile on the 
sides (not at the tips) of the branchlets ; very rare. 2. Globose tetraspores borne on 
the tips of the (then) shortened branchletee77S. 
Habitat. Our coasts occasionally. Yarmouth, Plymouth, &c. On rocks near low-water 
mark. Bare. 
Fig. 276. CALLITHAMNION COKYMBOSUM. 
Colour. A pink or purplish-red. 
Substance. Exceedingly soft, limp, and gelatinous ; having a fine gloss when dried. 
Character of Frond. Thread-like {filamentous)] jointed; excessively branched. Stem hair- 
like below ; cobweb-fine above (occasionally much more robust) ; closely set with 
long, alternate branches. Branches partly divided in a forked manner ; partly 
alternate ; re-branched in a similar way. The last series clothed with very com- 
pound, alternate branchlets. Branchlets zigzag ; set at every joint with cobweb-fine, 
repeatedly-forked branchletee77S, of nearly uniform length ; each tip, therefore, forming 
a roundish outline, something like those of C. spongiosum ; but not so bushy. 
Joints. Visible throughout ; even in the stems. 
Measuremeiit. From 1 to 3 inches long. 
Fructification. Of two kinds. 1. Minute spores in large, double capsules ; sessile in the angles 
of branching {axils). 2. Minute, round tetraspores, a single one sessile on one side of 
the forked branchleteews, immediately below the point where they fork. 
Habitat. South and West of England. West of Scotland. Isle of Man. Ireland generally. 
On rocks, algae, and Zostera marina near low-water mark. Not uncommon. 
Fig. 277. CALLITHAMNION FLOKIDULUM. 
Colour. A purplish-pink. 
Substance. Soft and almost spongy. 
Character of Frond. Dense tufts of fine, jointed threads {filaments), forming a roundish 
cushion on the rocks. Filaments equally slender throughout ; once or twice forked ; 
furnished with a few long, simple or forked, very upright branches ; the upper ones 
sometimes clothed near the top with a few secund or alternate, upright branchlets 
(the lowermost longest), on which the tetraspores are borne. 
Joints. Visible throughout under the microscope, or even through a pocket lens, having a 
peculiar shimmery appearance, from the silvery whiteness of the cell-membrane. 
Measurement. About an inch high. 
Fructification. Only one kind known. Minute, oval tetraspores, borne on very short, upright 
branchlets (or stalks), ranged in a secund manner along the upper branches. 
Habitat. West of Ireland. Orkney. Land’s End. Scilly. Isle of Man. On sand-covered 
rocks near low-water mark. Not uncommon. 
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