THE MARINE BOTANIST. 231 



observer of its identity with the common plants of 

 N. jpiirjpxireumP Whitsand Bay^ near Plymouth ; 

 once found gTowing in this locality by the Rev. W. 

 S. Hore^ in tolerable plenty. '^ I have visited the 

 spot/' he writes, ^^nay, the very rock, several 

 times since, at the exact time, but not a vestige of 

 it could I perceive." Kilkee. Miltown, Malbay. 

 Ballrig-gan. 



DUDRESNAIA. 



Name in honour of M. Dudresnay, a French Naturalist. 



Frond cylindrical, gelatinous, elastic ; the axis 

 formed of a lax network of filaments, coated with 

 longitudinal fibres ; the periphery composed of 

 forked moniliform filaments. Fructification : 1. 

 globular masses of spores attached to the filaments 

 of the periphery ; 2. external tetraspores^ borne by 

 the filaments of the periphery. 



