Ectocar2')ecB.'] sphacelaria. 155 



Genus XXYII. SPHACELAEIA, Lpighje. 



Gen. Char. Filaments jointed, rigid, distichonsly pinnated, 

 rarely simple, or subdicliotomous. Apices of the branches dis- 

 tended, membranous, containing a dark granular mass. Fructi- 

 iication, elliptical utricles, furnished with a limbus, borne on the 

 ramuli. — The name is from a Greek word signifying a gangrene, 

 alluding to the withered tops of the branches. — Harvey. 



SpJiacelaria are divided into two classes^ viz._, 

 ■^ Those whose fronds are beset with woolly fibres at the 



base or lower part. 

 ■^ ^ Those whose stems are naked at the base without 

 woolly fibres. 



■^ Stems clotlied at the base. 



1. Sphacelaria filicina^ Agardh. 



Hab. On rocks and INIuUipores near low- water mark, 

 and on the roots of Laminarice,'kc. Very rare. Found in 

 England by Mrs. Grifiiths, Mrs. Hare, Mrs. Wyatt, Mr. 

 Sconce, Mr. Ralfs, Dr. W. Arnott, Mr. Borrer, and very 

 fine by Mrs. Gulson at Littleham Cove,; in Ireland by Miss 

 Ball and Mr. "W. Thompson, and Dr. E. Harvey; and in 

 Jersey by Miss Turner and Miss White. Not found in 

 Scotland. 



Prom two to four inches high. Pinnae alternate; 



