HALF AN HOUK WITH SEAWEEDS. 43 



It takes its name from two Greek words signifying 

 "oak-tree." It possesses bladders, or air-vessels, 

 which in shape resemble pods, hence its specific name 

 of siliquosa. This species is very common on the 

 Welsh coasts, and everywhere it is a favourite with 

 the naturalist, on account of the numerous small 

 zoophytes, &c., it harbours among its dense fronds. 



The Rhodosperms comprehend the most beautiful 

 of all species of seaweeds, and hence they are most 

 sought after by collectors, and for ornamental pur- 

 poses. Their tints of scarlet and red are of various 

 shades, and the group includes species whose fronds 

 are not red at all. Nearly every species grows 

 submerged, and a large number of them in deep 

 water. The latter, therefore, can only be obtained 

 by dredging, or after a storm has uprooted them 

 and cast them ashore. Even then, unless you be 

 fortunate enough to gather them soon after they 

 have been cast up, they will be almost worthless for 

 herbarium purposes, on account of their being soon 

 acted upon by the sun, so as to lose their bright 

 colours. On the stems of Laminaria, above-men- 

 tioned, we may find the peculiar dark-red Poly- 

 siphonia urceolata, whose jar-shaped fruits are very 

 pretty objects when seen through a low magnifying 

 power. The Clilylodadia articulata, also, is a good 

 specimen to mount, because of the readiness with 

 which it adheres. This can easily be identified by 

 the jointed branches, whence its specific name. Un- 

 fortunately, however, it soon fades, even in the 



