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LIST OF THE BEITISH 



LXI. GlGARTINA. 



Frond cartilaginous, irregularly branched, purple or 

 very dark red, filiform, compressed or flat. Favellidia 

 in external tubercles. Tetraspores contained in dense, 

 immersed sori. 



1. Gigartina pistillata. 



2. ,, acicularis. 



3. „ Teedii. 



4. ,, mamillosus. 



LXI I. Chondrus. 



Frond cartilaginous, nerveless, compressed or flat, 

 dichotomously cleft, of very dense structure. Tetra- 

 spores collected into sori, immersed in the frond, and 

 scattered over its segments. 



1. Chondrus crispus. 



2. „ Norvegicus. 



LXIII. Phyllophora. 



Frond stipitate, rigid, membranaceous, nerveless, of 

 very dense structure. Tetraspores in superficial sori, 

 or in proper leaflets. 



