172 BRITISH SEA-WEEDS. 



best known of the Red division of the British sea-weeds. 

 The facility with which its flattened branches lay them- 

 selves out and adhere to paper, its elegant tree-like form 

 and brilliant lasting colour, have established it as the 

 prime favourite of unlearned sea-weed collectors, and 

 makers of sea-weed ornaments. It is generally distri- 

 buted all round our coasts, and, indeed, throughout the 

 temperate zone. It varies considerably in size and sub- 

 stance, and in the form of its branches, so much so that 

 some of the more slender specimens are liable to be con- 

 sidered a distinct species. Its general characters are, 

 however, sufficiently constant to be easily determined by 

 a careful examination. 



Genus LXXV. CORDTLECLADIA. 



Frond thread-like, irregularly branched, cartilaginous, 

 formed of two series of cells, those in the centre oblong, 

 longitudinal ; those on the surface roundish, minute, vertical. 

 Spores roundish, formed on branched threads, arranged in a 

 dense globular mass in spherical conceptacles without stalks; 

 tetraspores oblong, cruciate, immersed in pod-like branch- 

 lets. — CoKDTLEOLADiA, from the Greek chorde, a string, and 

 klados, a shoot. 



The sole representative of this genus in the British 

 flora — and it is doubtful if any other species exist else- 

 where — was formerly included in the genus Gracilaria, 

 whence it has been removed by Professor Agardh, for 

 reasons already referred to in speaking of the Order 

 Rhodymeniaceee. 



Cordylecladia erecta. The erect Cordylecladia. 



Fronds two or three inches high, cylindrical, thread-Kke, 



