CERAMIACE.E. 203 



* Phycologia/ but in his later works he has degraded it 

 to a variety. 



C. rubrum, var. proliferum. 



Frond forked, beset on all sides with numerous simple or 

 forked brancblets ; nodes and internodes densely covered 

 with cells. Spore-clusters generally destitute of branchlets. 



This was formerly C. boti'yocarpum, figured plate 215, 

 Harvey's ' Phycologia Britannica.' 



C. rub rum, var. secundatum. 



Similar to the last variety, but with secund branches. 



C. rubrum, var. pedicellatum. 



Fronds sparingly branched ; branches scattered ; nodes 

 and internodes coated with coloured cellules. 

 Figured in Harvey's ' Phycologia/ plate 181. 



Ceramium diaphanum. The transparent 

 Ceramium. 



Fronds from two to six inches long, as thick as a bristle 

 below, becoming gradually thinner towards the upper part, 

 irregularly forked ; branches set with short, forked branch- 

 lets, with forcipate tips ; nodes swollen, coated with purple 

 cellules ; internodes transparent, those of the main stem 

 three or four times as long as broad. Spore-clusters near 

 the tips of the branches, surrounded by involucral branch- 

 lets ; tetraspores sunk in the nodes. 



This is the largest and handsomest of our British 

 Ceramia, and is very easily recognized by its numerous 

 branches, its large size, and distinctly chequered stem. 

 Its colour varies from a delicate pink to a dark purple. 



