144 SEA MOSSES. 



uating as they branch. It grows to the height of 

 from one to three inches, and sometimes more. I 

 have found it at Wood's Holl, five inches high. It 

 is invariably dark brown or black on paper, does 

 not colapse when taken from the water, and is 

 covered pretty thickly, main stem and branches, 

 with thorn-like, simple or branched spines, one-tenth 

 af an inch or less long. The arietina, or "ram's 

 horn " variety, has the end branchlets and spines 

 recurved or hooked. At Peconic Bay, Harvey says, 

 the natives call this variety " Nigger hair." I have 

 found the common form plentiful at Silver Spring, 

 Providence River, Wood's Holl, and Marblehead, in 

 July and August. Miss Booth reports it at Peconic 

 Bay, in September. Mr. Collins, at Lynn beach, on 

 Zostera, as late as October, and Mrs. Davis finds 

 it all summer in the " Mill Pond," at Gloucester. 



POLYSIPHONIA OlNEYI, HaRV. 



It is agreed by Dr. Farlow and Prof. Eaton 

 that this is but an extreme variety of P. Harveyi, 

 and Dr. Farlow is of the opinion that both species 

 are identical with the older European species, P. 

 spinulosa, Grev. P. Olneyi differs from P. Harveyi, in 

 being a somewhat larger plant, composed of much 

 softer, and finer filaments, longer and straighter 



