OLIVE COLORED ALG^E. 110 



and a smaller plant from the island of Spitsbergen, 

 collected July 23rd, has them half an inch or more 

 long. When these pencils fall away, they are 

 replaced by short, sharp, awl-like spines, set regu- 

 larly and alternately on each edge of the flattened 

 branch, pointing forward. It is, perhaps, an arctic 

 plant, but it is found in temperate waters, south of 

 Cape Cod. It is said sometimes to attain a height 

 of six feet. It is an interesting plant, and the 

 young forms are very beautiful, and adhere nicely to 

 paper in mounting. 



Desmarestia ligulata, Lam. 



This is the most common California species, and 

 exceeds in interest, if not in beauty, either of our 

 Atlantic plants already named. It grows a foot or 

 high, flat, one-fourth to one-half inch wide, 

 beset, at intervals, along the edges, by pairs of op- 

 ; ite flat branch* And these, again, are more 



thickly clothed by shorter, flat branchli ser- 



d along the edges with sharp, forward-pointing 

 teeth. 



I ;uli tin- primary and indary branches are 



narrowed to a point at base and ap The sub- 



stance of the frond i^ thin and delicate ; the color, 

 a yellowish olive, in the specimens which I have 



