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 ^Eolian's sweet aerial notes," 



The height of the polypidom is an inch and upwards, 

 dichotomously divided ; cells numerous. 



Genus XXIV. VESICULARIA, /. V. Thompson. 



Gen. Char. Polypidom rooted, confervoid, fistular, liorny, di- 

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

 junct, uniserial and unilateral. 



1. Yesicularia spinosa, Silk Coralline, Dillenius. (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 



