HANDBOOK OF SEA- WEEDS. 17 



The next group, the Laurenciaceae, are cartilaginous and cylin- 

 drical or compressed, the frond in the greater portion of them 

 being inarticulate and solid. They contain several species valued 

 by collectors, although some of them are amongst our com- 

 monest plants. Their colour is, when perfect, a dull purple or 

 brownish red, but they change under the influence of light and 

 air, while fresh water is rapidly destructive to their tints. (Fig. 10.) 



Fig. 10. Laurencia pinnatifida. 



The Chylocladias are curiously jointed plants, removed by 

 Agardh to a new genus, Lomentaria, and a new order Chondriae. 

 Bonnemaisonia asparagoides is the most rare and beautiful of 

 the tribe. 



The last tribe of red weeds, Rhodomelaceoe, varies greatly in 

 the structure of the frond, but the fruit is more uniform. Poly- 



B 



