248 SEA MOSSES. 



found on the coast of California, and in the north 

 Pacific very common. 



Ptilota elegans, Bonnem. 



This is a much more delicate plant than the last, 

 narrower, thinner and of a darker color. It is common 

 from New York northward. It may be found almost 

 always growing upon the perpendicular sides of cliffs, 

 under the overhanging " Rockweed," near low-water 

 mark. That is the only situation in which I have 

 ever seen it growing. But I have collected it in no 

 little abundance about the beach, at Newport, in the 

 summer and fall, among the mass of sea weed left 

 by the waves. There, it must grow in deep water. 



The fronds are nearly cylindrical, but branch 

 like the last, from opposite sides in one plane, decom- 

 pound pinnate, the pinnse and pinnulae opposite and 

 alike, though, I think, in most cases one of them is 

 apt to be much smaller than the other. The large 

 and small parts alternate, so that the symmetry of 

 the frond is maintained. Often the smaller pinnule 

 is suppressed altogether, and the branching will thence 

 seem to be alternate. 



The ultimate ramuli are composed of a single row 

 of square or oblong cells. This is a fine, delicate 

 and beautiful plant. It adheres well to paper. The 



