368 HISTORY OF BRITISH ZOOPHYTES. 



summon the Dryads, and convert them into a marine band 

 of Nereids, there might, from groves of tangle, burst forth 



music, 



" Like harp JMian's sweet aerial notes." 



The height of the polypidom is an inch and upwards, 

 dichotomously divided ; cells numerous. 



Genus XXIV. VESICULAEIA, /. V. Thompson. 



Gen. Cliar. Polypidom rooted, confervoid, fistular, horny, di- 

 chotomously branched, jointed at the divisions : cells ovate, dis- 

 junct, uniserial and unilateral. 



1 . VESIC CLARI A SPINOS A, Silk Coralline, Dillen ius. ( Plate 

 XX. fig. 77.) 



Hab. On oyster-beds, Dr. Fleming; shores of Ireland, 

 W. Thompson; Mersey, Mr. Tudor; Leith shore, D. L., jun. 



This, from its fineness, has been called Sea-silk Coral- 

 line : the stem is formed by fine silken threads, united, and 

 the ramifications arise from this with a zigzag stalk. In 

 the small branches appear rows of holes with a rim, as if 

 bored from within outwards. The vesicles are of an oval 

 shape, and open at the top. They are so delicate that they 

 can with difficulty be seen ; but when they are seen, they 



