194 BRITISH SEA-WEEDS. 



without being eatable, and the ' Comedy of Errors' may 

 be considered to be complete. It grows near low-water 

 mark, is perennial, and fruits in winter. It occurs on 

 all parts of the British coast, from Orkney to the Channel 

 Islands, and indeed extends far beyond these limits, 

 both north and south. The only variation to which it 

 is liable is that of size, but the fronds are frequently 

 much torn and altered in appearance by the action of 

 the waves. 



Schizymenia Dubyi. Duby's Schizymenia. 



Fronds from a few inches to a foot long, and three to five 

 inches wide, commencing with a very short, flattened stem, 

 which gradually expands into a thinnish, fleshy, membranous 

 oval disc, waved at the edge. Spore-clusters very minute, 

 enveloped in a transparent membrane, and disposed beneath 

 the surface of the frond, slightly prominent ; tetraspores 

 not known. 



This plant, formerly Kallymenia Dubyi, grows between 

 the tide-marks in sheltered positions. It is annual, and 

 in perfection in early summer. It is more rare than 

 Schizymenia edulis, and is distinguished from that species 

 by its shorter stem, and the much thinner substance of 

 its frond. I recently received some very fine specimens 

 of this handsome plant from that successful collector 

 Mr. J. Gatcombe, who gathered them at Plymouth. 



Genus XC. CATENELLA. 



Frond nearly tubular, constricted, membranous, of a dull 

 purple colour; the axis composed of a network of ana- 

 stomosing, longitudinal filaments, from which are emitted 



