OLIVE COLORED ALG^. 117 



Sub-order — DESMARESTIEM. 

 Genus.— DESAfARESTIA* Lam. 



Of this genus we have four species, divided 

 equally between the two oceans. The cyHndrical 

 and narrow forms belong to the Atlantic and the 

 flattened or strap-like forms are natives of the 

 Pacific. It is not a little singular that one species, 

 D. ligul.ita, should be very common on the eastern 

 shores of both the Atlantic and Pacific oceans, and 

 not found at all on the coast lying between, viz., 

 the western shores of the Atlantic. 



Desmarestia viridis. Lam. 



This is a large and fine plant, growing from one 

 to three feet in hight, of a beautiful chestnut oliv* 

 color when fresh, turning to a dark green when 

 dry. It is found on rocks, stones, a.nd other Algae, 

 in tide pools near low water mark, and in deep 

 water. The frond is cylindrical or filiform, twice as 

 thick as a bristle in a plant two feet long, beset, at 

 rather remote intervals, with long, primary branches, 

 which come out in pairs exactly opposite each other 

 on the two sides of the main stem. These branches 

 are themselves branched in the same way by pairs 



* Desmarestia was named for Desmarest, a French Naturalist. 



