Fig. 211. GYMNOGONGRUS PLICATUS. 
Colour. Dark-purple ; fading to pinky and white. 
Substance. Eemarkably horny and stiff. 
Character of Frond. Like fine wire ; of one thickness throughout. Cylindrical ; slender ; 
entangled ; often in large bundles ; very irregularly branched ; partly forked 
{dichotomous), partly alternate or secund (two or three branches on one side in 
succession) ; more or less furnished with short branchlets, horizontally set, and some- 
times spreading in all directions. All the angles of branching {axils) rounded. 
Measure7nent. From 4 to 10 inches long. 
Fructification, Only one kind found ; and that imperfectly understood. Oblong warts em- 
bracing the stem, composed of very slender, jointed radiating threads. 
Habitat. Our rocky shores generally. On rocks between tide-marks, and at a greater depth. 
Common. 
Now Ahnfeldtia plicata. For another Gymnogongrus, see Plate XLIV. Fig. 200. 
Fig. 212. POLYIDES ROTUNDUS. 
Colour. Brownish-purple ; becoming much darker in drying. 
Substance. Between gristly and fleshy ; solid ; elastic. 
Character of Frond. Cylindrical ; of one thickness throughout (about that of whip-cord) ; 
repeatedly forked {dichotomous) ; the tips cut to one level, forming a rounded outline ; 
the last forkings short ; angles of division {axils) rounded. Tufted. Root a wide- 
spread disc. 
Measurement. From 4 to 6 inches high. 
Fructficatio7i. Of two kinds. 1. Clustered groups of spores, nestling among threads, in large 
oblong, but irregular, spongy warts, ’which are pink when fresh ; external ; embracing 
the stems. 2. Tet7^aspo7^es deeply imbedded in swollen upper branchlets. 
Habitat, Our coasts generally. On rocks and stones between tide-marks. Common. 
Yery like Furcellaria fasiigiata. I>istingiiishal)le, however, by its disc root; and its spongy 
parts of fructification when tliese are present. Otherwise by its 7'ouiided axils and the short- 
ness of the last forkings. 
92 
