THE SHORES OF BRITAIN. 55 



for singularity or beauty, and then dismiss these in- 

 teresting tribes. The common Sea-thong {Himan- 

 thalia lorea), 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 twentvYeet. 

 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), a 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 



