GREEN ALG^. 59 



Cladophora uncialis, Fl. Dan. 



As its name implies, is about an inch long. I 

 have found it growing in tide pools, or on the rocks 

 near low tide, in little globose tufts, about an inch 

 across, and of the same height. The tuft grows from 

 a mass of matted root-fibres. It is more or less closely 

 matted together by reason of its wide and irregular 

 branching. When growing, the plant is of a bright 

 green color, which will be discharged if it is put into 

 fresh water. When dry it is quite a yellowish green, 

 lighter still toward the centre of the tuft. The cells of the 

 main stems and branches are of nearly imiform length, 

 and two or three times longer than broad. My plants 

 are all from Marblehead where they were collected 

 in midsummer. Mr. Collins finds this plant in the 

 same localities, seasons and situations, as the C arcta^ 

 which it resembles not a httle. My other correspond- 

 ents do not report it, though no doubt it may be 

 found along our whole northern coast. 



Cladophora rupestris, L. 



The Cladopliora "of the rock," is a very distinctly 

 marked species. It grows between tides and below. 

 Its best forms are to be found in tide pools near low 

 water mark, or on the perpendicular sides of rocks, 



