Plate LVI. 
Fig. 256. CALLITHAMNION BARBATUM. 
Colour, A brownish or full red. 
Substance. Membranaceous, and somewhat rigid. 
Character of Frond. Dense tufts of jointed threads ; irregularly branched. Stems 
rising from creeping fibres bearing opposite, or sometimes alternate, branches. These 
long, and either simple or clothed for half their length (and irregularly here and 
there) with minute, opposite, spine-like branchletee?is, which die down in winter. 
Joints. Visible throughout* ; deeply coloured. 
Measurement, From 1 to 2 inches long. 
Fructification. Only one kind known. Narrow oval tetraspores, sessile on the lowermost 
joints of the branchletee?25. 
Habitat. Ilfracombe, Penzance, and Weymouth. On mud-covered rocks within tide-marks. 
Very rare. 
* “ When examined under the microscope," must always be understood in speaking of 
these delicate plants. 
Fig. 257. CALLITHAMNION BRODI^I. 
Colour. A brownish-red. 
Substance. Soft generally ; stem elastic. 
Character of Frond. Thread-like {filamentous) ; jointed ; tufted or single ; much branched. 
Stems hogs’-bristly below, becoming finer above ; generally simple ; furnished 
throughout with long, alternate, wide-spread branches, the lowermost longest. These 
bearing a secondary set, one to each joint, which spring in succession from each side 
of the stem {quadrifariously) ; the lowermost always longest ; so that each branch 
has a spear-shaped outline. Secondary branches once or twice re-branched in the 
same way. Last branchlets somewhat back-curved ; bearing towards their tips 
a few secund branchleteews. 
Joints. Obscure in the stems, which are somewhat opaque and veiny ; visible in the branches 
and branchlets. 
Measurement. From 1 to 3 inches long. 
Fructification. Of two kinds. 1. Minute sj9ores in large, roundish, solitary, or double capsules; 
sessile on the branchlets. 2. Globose tetraspores^ sessile on the branchleteews. 
Habitat. Our coasts gelierally. On algge near low-water mark. Eare. 
Fig. 258. CALLITHAMNION BRACHIATUM. 
Colour. Brownish-red ; becoming darker in drying. 
Substance. Eigid for so delicate a plant. 
Character of Frond. Thread-shaped (^Z7/orm) ; jointed ; tufted or single; much branched. 
Stem the thickness of a hog’s bristle ; simple, or nearly so ; set with branches which 
spring in succession from all sides {qiiadrifariously). Branches often re-branched 
in the same way ; last set but one, slender, drawn out ; furnished with short, 
alternate tufts of branchlets. Branchlets upright, awl-shaped ; not tapering to 
the base, but gradually upwards to a fine point. 
Joints. Obscure in the main stems, which are somewhat opaque and veiny ; visible in the last 
branches and branchlets. 
Measurement. From 1 to IJ inches long. 
Fructification. Only one kind known. Minute, oval tetraspores, sessile near the tips of the 
branchlets. 
Habitat. Our coasts generally. Parasitic on the larger algas. 
Probably only a slender variety of C. tetrayonum. 
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