Plate LVII. 
Fig. 262. CALLITHAMNION ARBUSCULA. 
Colour. Dark clarety-red, or brown. 
Substance. Stems gristly ; brancblets very soft. 
Character of Frond. Thread-like {filamentous) ; jointed ; single or tufted ; excessively 
branched ; bushy. Stem thick at base ; often shaggy with fibres ; bare at first ; then 
set with irregular, alternate branches. Branches twice or thrice re-branched with 
shorter ones, which spring from all sides of the stem {quadrifarious) ; and are all 
densely clothed with minute, overlapping branchlets, also quadrifarious. Branchlets 
plumed with pointed, spreading or back-curved, simple or forked branchleteews, 
springing from each joint. 
Joints. Only visible in the branchlets and branchleteews. 
Measurement, From 3 to 8 inches long. 
Fructification, Of two kinds. 1. Minute spores in large roundish capsules; sessile, two or 
three together on the branchlets. 2. Globose tetraspores, sessile on the inner side of 
the last branchlets. 
Habitat, Western shores of Scotland and Ireland, abundant. East coast of Scotland, rare. 
Filey, plentiful on the north side of the bridge. On rocks and mussel-shells, &c., 
from half-tide level to low-water mark. 
Not found on the same stations as C. spongiosum. 
Fig. 263. CALLITHAMNION FLOCCOSUM. 
Colour. A bright purplish-lake. 
Substance, Very soft and flabby. 
Character of Frond. Dense tufts of hair-like, jointed threads {filaments) much branched at 
intervals. Stems very slender ; irregularly divided into several principal branches, 
which are again once or twice forked {dichotomous). Branches naked, or furnished 
at rather remote intervals with short, many-times-divided (almost tufted), alternate, 
lesser branches. Every joint of the whole plant bearing a pair of exactly opposite, 
very short, very slender, pointed branchleteews. 
Joints. Visible throughout. 
Measurement. From 1 to 5 inches long. 
Fructification, Only one kind observed. Oval tetraspores borne on the branchletee? 2 S near 
their base. 
Habitat. North of Scotland (Orkney, Aberdeen, &c.). On rocks near low-water mark. Very 
rare. 
The fringing branchleteews of this plant form so distinct a character that it is impossible 
to mistake it for any other species. 
113 
Q 
