140 SEA MOSSES. 



gray, November sky, and the sea a steel blue, cold 

 and angry, I found this among the most plentiful 

 of the late autumnal "Sea Mosses." Displayed with 

 taste, it makes an elegant picture on paper. A 

 comparatively light pressure should be put on it at 

 first, in drying, else its tender frond will be crushed 

 and ruined. 



Genus.— POLYSIPHONIA* Grev. 

 This is the largest genus of Red Algae. Agardh 

 in his latest work, enumerates no less than 129 un- 

 doubted species. Many more have been proposed 

 by other writers. About thirty species belong to 

 our American flora. But several of them are pecu- 

 liar to the sub-tropical region of Florida, and will 

 not come within our reach. Others are too rare or 

 insignificant to be enumerated in this work. But 

 all such as are likely to be met with, at all 

 common, will be described. The color of these 

 plants ranges between the browns and a full black ; 

 only three, herein described, show traces of red : 

 P. ltrceolata, commonly, and P. violacea and P. 

 Olneyiy occasionally. On the fertile fronds, the 

 beautiful, little egg-shaped fruit-holders will be easily 



* Polysiphonia = Many tubes; referring to the internal structure of the 



frond. 



