ern species of Ci/stophora, distinguished from other distichous 

 species by its slender, terete or nearly terete stems and branches, 

 and by its very loose ramification, and long, but not torulose re- 

 ceptacles. In general aspect it may be compared to the Cysto- 

 seira fibrosa of the northern hemisphere. 



Fig. 1. Cystophora Grevillei, part of a frond, — the natural size. 2. Section 

 of a receptacle. 3. A spore, antlieridia, and paranemata : — variously mag- 

 nified. 



