RED ALG^. 173 



The cylindrical stem flattens into a midrib, directly 

 it enters the leafy part of the frond. There is but 

 a very narrow margin of leaf, or wings, bordering the 

 midrib ; in our plants, it is not over one-eighth to one- 

 fourth of an inch wide. The frond rapidly forks or 

 irregularly divides, in one plane, so that the frond 

 has a multitude of narrow, terminal ramifications, 

 along towards the end of which, the midrib, in most 

 of our American plants, seems to disappear. 



The margins of the lobes are usually entire, and 

 they run out commonly to a narrow, but always 

 rounded, termination, nearly one-tenth of an inch wide. 



It will often be found associated with Euthora 

 cristata, from which it will sometimes be found diffi- 

 cult to distinguish it, on account of similarity of size 

 and ramification. But the small ends of the Eutho7\i 

 are never rounded, but always square or notched, 

 in an angular fashion. A common pocket lens will 

 always reveal the distinction, if it cannot be made 

 out with the unaided eye. D. a/a fa is a perennial. 

 It has not been found south of Cape Cod, but it 

 will seldom be wanting on our northern shores. It 

 is noc uncommon on the California coast. Its color 

 is a light red or delicate pink. It is indeed a very 

 beautiful plant when carefully mounted. Our Amer- 

 ican plants seem to adhere well to paper. 



