RED ALGA2. 221 



GlGARTIXA RADULA,* AG. 



This, and the remaining species of this genus, 

 are exclusively natives of the Pacific coast. This is 

 the largest and most pretentious species of the genus. 

 I: has a large, flat, thick, dark, livid red frond, which 

 takes on in different plants quite a variety of forms 

 and outlines. But in the main, it is simple, or if 

 divided, then only by the presence of one or two 

 clefts of greater or less depth. 



It puts out no branches or leaflets, but is more 

 or less thickly peppered over with warty protuberances, 

 which seen along the edges of the frond in profile, 

 appear to be mostly minute globes, a half or a quarter 

 as large as a pin head, set upon short stalks. 



The frond itself rises from a short, flattened stem, 

 from which it more or less rapidly widens to a breadth 

 of several inches, then, in the simpler forms, rounds 

 off, usually very bluntly, at the top. The largest speci- 

 men in my herbarium is fourteen inches long, and six 

 inches wide in the middle, tapering more rapidly 

 and acutely to the top than to the bottom. But another 

 specimen, ten inches long, and four and a half broad, 

 tapers quite acutely to the base, and is very broad 

 and blunt at top, even cut in, heart-shaped. 



* Radula ■ A scraper. 



