376 THE SEA SHORE 



attached to rocks or to other weeds. It is in its best condition 

 during the summer, when we may see its oval spore-conceptacles 

 and the tetraspores in distorted branchlets. 



The last genus of the Rhodomelacece is Dasya, which contains 

 some very graceful and brightly-coloured weeds that are found 

 principally on our south and west coasts. In these the fronds 

 are thread-like or flattened, branched, and without visible joints. 

 The main stem contains many tubes, but the tubular structure 

 is hidden by the outer layer of cells ; and the branchlets, which 

 are slender, one-tubed, and jointed, bear little lanceolate pods that 

 contain the tetraspores. 



D. ocellata has small tufted fronds, about two or three inches 

 long, attached to a small discoid root. The main stems are densely 

 covered with slender, forked branchlets, those at the tips being 

 clustered in such a manner as to recall the eye-like marks of the 

 peacock's tail. It grows principally on the mud-covered rocks 

 beyond low-water mark, and is not by any means a common weed. 

 Another species D. arbuscula is somewhat plentiful on parts 

 of the Scottish and Irish coasts, but comparatively rare in South 

 Britain. It has a small disc -like root, and stems thickly clothed 

 with short branchlets. The spore-conceptacles are tapering, on 

 short stalks, and the tetraspores are contained in pointed pods on 

 the branchlets. The scarlet Dasya (D. coccinea) may be commonly 

 seen at and beyond low-water mark during late summer, at which 

 time splendid specimens may also be found on the beach after 

 storms. Its stem is thick, proceeding from a discoid root, and 

 is clothed with hair -like filaments; and the branches bear short, 

 slender branchlets that give them a feathery appearance. The 

 tetraspores are contained in elongated, pointed, and stalked pods. 

 There are three other species on the British list, but they are not 

 common weeds. 



The last of the three great groups into which the sea weeds 

 are divided is the Melanospermece, or olive-spored algae, the different 

 species of which are generally very readily distinguished by their 

 olive-green or olive-brown- colour, for the whole plant, as well 

 as the spores, contains a dark olive colouring matter, in addition to 

 the chlorophyll which is always present. 



These weeds are often very large, frequently attaining a length 

 of twenty feet or more in our seas, and from eighty to a hundred 

 feet in warmer parts ; and, being also extremely abundant almost 

 everywhere, they form a most conspicuous feature of the shore. 



