266 SEA MOSSES 



This plant grows from one to three inches high. 

 It has a somewhat robust leading stem with several 

 stout primary branches, differing in this respect from 

 C. byssoides, but the final branchlets and ramuli are 

 extremely fine and delicate, and somewhat long. 



A variety of this species, seirospermum, differs 

 from the typical form by being a trifle stouter and 

 coarser, with the ultimate ramuli not so abundant or 

 so long and silky. It has, however, much the same 

 habit of growth, and with the aid of a good lens, 

 may be determined without difficulty, when in fruit, 

 by the singular strings of bead-like spores which it 

 produces in the place of the common, asexual tetra- 

 spores. The tetraspores of this genus grow externally 

 up the ultimate ramuli. 



This species is reported from New York north- 

 ward, but it cannot be common in northern waters, 

 for none of my correspondents have found it in that 

 region. But it is not very rare south of Cape Cod. 

 I have taken numbers of plants, var. seirospermum, 

 at Wood's Holl, in July. Miss Booth gathered the 

 same at Orient, in July. I have a number of ex- 

 quisite plants of the normal form, sent to me by 

 Mrs. Woodward, from Cottage City, Martha's Vine- 

 yard. I understand them to be winter plants. One 

 of them is represented in Plate XVIII. 



