RED ALG^. 183 



slender at first, but gradually widen as they grow 

 upward. Another division, soon occurs in each of 

 these, and the parts again expand, and so on. This 

 method of growth, together with the partings or 

 branchings which occur along the edges of the 

 frond, and which likewise have the same habit of 

 upward widening, gives the whole frond a decidedly 

 fan-shaped aspect. 



In July or August, tlie seed-vessels appear along 

 the edges of the branches, like warts, as big as 

 pigeon shot. The substance of the frond is some- 

 what tender and brittle, but when dry, it is tough 

 and leathery. The color is a dull purplish-red, but 

 much darker when dry and mounted on paper, to 

 which it adheres rather imperfectly. 



Order.— CORALLINES. 

 Genus.— CORALLINA* Lam. 



There are several genera of this order growing on 

 our shores, besides the one named above. They are 

 all characterized by the calcarious, or stony incrusta- 

 tion of the frond. Some of them are mere pink 

 or brown patches, upon the fronds of other Algae, or 



* Corallina ^ A little coral. 



