2-3 feet long or more, not twice as thick as hog's-bristle, more or less 

 densely covered with minute, gland-like, filiform processes, spreading to all 

 sides, the lower pair commonly denuded of branches, the upper closely set 

 with spirally or irregularly inserted lateral branches, 3-8 inches long. 

 Secondary branches filiform, pinnated in their lower half with slender, simple, 

 ramuliform leaves, which bear in their substance usually three ovoid, separated 

 vesicles ; in their upper half bi-tripinnate, with fewer vesicles. Receptacles 

 formed at the ends of the branches, from the terminal ramuli or leaflets, at 

 length somewhat racemose. Colour a full-olive, turning black in drying. 

 Substance coriaceous when recent, rather brittle when dry. 



The genus Cystophjllum holds an intermediate place between 

 Cystoseira and GystopUora ; from the former it differs in having 

 the vesicles seriated in the ultimate undivided YdiVuxAi or " leaves," 

 instead of in the larger or penultimate branches ; and from the 

 latter in having vesicles in the ordinary " leaves," and remote 

 from their apices, instead of terminal on specially metamorphosed 

 leaves, distinct from the ordinary. 



C. muricatum is the commonest species, and is found through- 

 out the Indian Ocean, as well as on the Australian coast. In 

 Australia it generally grows in sheltered harbours, and in such 

 situations is often very much covered with minute zoophytes and 

 other parasites. 



Fig. 1. Cystophyllum MURICATUM, — the natural size. 2. Fertile apices, con- 

 verted into receptacles, — enlarged. 



