(4) 



moniliform series. Substance coriaceous, hard and woody in the older 

 parts, not at all adhering to paper. Air-vessels minute, solitary, im- 

 mersed in the substance of the branches near the apex. Receptacles 

 " formed in the apices of the branches, oblong cylindrical, becoming 

 nodose, always armed with spine-like ramuli, similar to those that clothe 

 the branches ; " " spores obovate, with wide borders." When growing 

 under water, the frond reflects beautiful prismatic colours, which are 

 lost when it is lifted into the air ; the colour is then a yellowish olive. 



The very appropriate name ericoides has been bestowed upon this 

 species, from its shrubby and heath-like character of the fronds, both 

 from their rigid substance and the small leaf-like processes which cover 

 them. This shrub-like character is the more striking when the fronds 

 grow erect as they sometimes do, and then the plant has perhaps more 

 the appearance of a stunted miniature crab-tree than a straggling bush 

 of heath, which it more nearly resembles in its leaf-like ramuli than in 

 its general habit. This singular shrub-like character it retains even in 

 the herbarium, but the peculiar character, for which it is most remarkable, 

 and which renders it so much a gem in its native element, is the power 

 it possesses of decomposing the rays of light, and reflecting all the 

 colours of the rainbow. 



Nothing could exceed the gorgeous brilliancy of these plants in their 

 native rock -pools, especially when the water is slightly agitated. No 

 pen or pencil could possibly do justice to the portraiture of this lovely 

 gem when draped in all the richness of its lucid garniture. The most 

 brilliant play of light of ever-varying tints of blue and green, of purple 

 and azure, are rapidly and lavishly thrown from branch to branch as 

 the fronds gently wave to and fro in the gentle swell. The play of light 

 much resembles that observed in Chondrus crisious, mamiUosus, and some 

 others ; but is infinitely more varied and beautiful. No sooner, how- 

 ever, has the plant been removed from the water, than all this gorgeous 

 display of colom-ing vanishes, washed off as it were with the fluid which 

 streams into the pool, and nothing remains but the plain and sombre 

 tints of green and brown ; even these disappear in the herbarium, and 

 the term nigrescens would then be much more appropriate to its dull 

 and lack-lustre hue. 



EXPLANATION OF PLATE CXXXL 



Fig. 1. — Cystoseira ericoides, natural size, 

 2. — a, vesicle ; &, receptacle. 

 S. — Section of receptacle. 

 4. — Section of conceptacle. 

 5. — A spore. All magnified. 



