Fig. 259. CALLITHAMNION TETRICUM. 
Colour. A dull piirplish-red or brown. 
Substance. Rigid and harsh, but very fragile when once dried. 
Character of Frond. Thread-shaped {filiform) ; jointed ; tufted or single ; much branched. 
Stems short and shaggy ; dividing into several principal branches. Branches several 
^ times re-branched ; ropy ; closely furnished throughout with straight, rigid, hair- 
like branchlets ; some simple ; some clothed with short, regularly-set, alternate 
branchletee?zs. 
Joints. Obscure in the stems ; visible in all the branches. 
Measurement. From 2 to 8 inches long. 
Fructification. Of two kinds. 1. Minute spores in large oval capsules, generally in pairs, 
sessile near the tips of the branchletee?zs. 2. Minute, oval tetraspores, sessile on 
little stalks which spring from the branchletee?2S. 
Habitat. South of England. South and west of Ireland. On perpendicular sides of rocks, 
between tide-marks. Frequent. 
Fig. 260. CALLITHAMNION ROSEUM. 
Colour. A fine purple-red when young ; when old, brownish ; becoming brighter in fresh water. 
Substance. Very soft. 
Character of Frond. Tufts of slender-jointed threads {filaments)', excessively and loosely 
branched ; often entangled. Stems set throughout with long, wavy, spreading 
branches, which are re-branched in a similar way. Secondary set furnished with 
branchlets, beautifully and regularly plumed like a feather with branchleteens. 
Joints. Visible throughout in young plants ; in older, the stems opaque and full of veins. 
Measurement. From 3 to 4 inches long. 
Fructification. Of two kinds. 1. Minute spores m clustered capsules, sessile on the branchlets. 
2. Oval tetraspores, sessile on the inner side of the branchletee/is. 
Habitat. Our shores generally. On rocks and the larger Fuci, near low- water mark. Also 
in estuaries and muddy places. Not uncommon. 
Fig. 261. CALLITHAMNION TRIPINNATUM. 
Colour. A fine crimson. 
Substance. Soft and delicate ; closely adhering to paper. 
- Character of Frond. Tufts of jointed threads {filaments) ; much branched ; the whole plant 
at one level. Stems furnished throughout with irregularly alternate branches. 
Branches set throughout with regularly alternate branchlets, beautifully plumed like 
feathers. Upper branchletee?25, longish ; lower, short, or altogether wanting ; one, 
however, always rising at the base of each branchlet. 
Joints. Visible throughout, even under a pocket lens. 
Measurement. From 1 to 2 inches long. 
Fructification. Only one kind observed. Oval tetraspores, sessile on the branchletee/is. 
Habitat. West of Ireland. On rocks at extreme low-water mark. Very rare. 
The solitary branchletee?? rising from the angles of branching (axils) distinguishes this 
plant from C. Borreri, which it otherwise much resembles. 
