114 SEA MOSSES. 



Ectocarpus Farlowii, Thuret. 



This is a shorter and somewhat coarser plant 

 than the preceding, growing in the same situations 

 upon Fucus nodosus. In my specimens, the end of 

 the Fucus is clothed, for the space of three inches 

 or more, with a dense, dark green mass of Ectocarpus 

 filaments, half an inch long. I have seen no detailed 

 description of the plant; but perhaps its outward 

 appearance, as given above, being somewhat distinct 

 and well-marked, would serve most collectors as a 

 clue to identification, better than a fuller account of 

 the fruit and branching. I found it common at 

 Marblehead, in the summer. It is also found along 

 the coast north, as far as Peak's Island, Maine. 



Ectocarpus siliculosus, Lyngb. 



This plant is very common along our whole 

 eastern coast, and is found occasionally on the 

 Pacific shores. It grows on various substances be- 

 tween tides, but seems especially to affect the string- 

 like fronds of the Chordaria flagelliformis . The 

 color is mostly a yellowish green, but variable. Fronds 

 from three to six inches long, not entangled, filaments 

 very slender, and excessively branched, all the divisions 

 alternate with acute axils. The propagula are formed 

 by the transformixig of a portion of the ultimate 



