THE SHORES OF BRITAIN. 55 
for singularity or beauty, and then dismiss these in- 
teresting tribes. The common Sea-thong (Himan. 
thalia lorex), so generally distributed, is worthy of 
observation on account of its curious mode of growth. 
From a shallow cup, affixed to the rock by a short 
foot-stalk, spring two or three long, olive-coloured 
straps, each of which becomes divided into two, and 
each of these into two more, in succession: these 
attain commonly the length of eight or ten feet, 
and have been asserted to reach even twenty feet. 
The thongs have been usually considered the fronds 
of this species; but Dr. Greville thinks that the sin- 
gular cup is the true frond, and the thongs the re- 
ceptacles of the seed greatly lengthened. The surface 
of the thong is studded with. tubercles, from which 
are discharged the seeds, accompanied with much 
mucus, through the pores. The cup of this, species 
has been occasionally observed on exposed rocks, 
swollen into a large hollow smooth black ball, ex- 
actly round, perhaps caused by the heat of the 
sun rarefying and expanding the contained air, or 
being perhaps the indication of a diseased state of 
the plant. 
A very remarkable form, and one of singular 
beauty, is presented by the Peacock’s tail (Padina 
pavonia), ® species not uncommon, attached to 
rocks at the bottom of still, and generally shallow, 
marine pools. The fronds rise in form of a rounded 
fan, of a yellowish-olive tint, elegantly marked with 
concentric zones or bands, of a dark brown. One 
side, and sometimes both, is generally hoary, as if 
dusted with powder, and the outer edge is delicately 
