114 BRITISH SEA-WEEDS. [_Melanospermece. 



Genus YI. HIMANTIIALIA, Lpifjhi/e. 



Generic Character. Frond coriaceous, orbicular, pezizaeform. 

 Vesicles none. Eeceptacles elongated, strap-shaped, compressed, 

 dichotomously divided, springing from the centre of the frond, 

 containing immersed tubercles, furnished with a pore. — Greville. 



1. IIiMANTHALiA LOREA, Lijiigh. (Plate lY. fig. 13.) 

 Hab. On rocky shores, common. Annual? Biennial? 

 High authorities give different answers on this point. 

 Some regard it as annual, as the thongs are produced 

 every year : but others say that the long thongs arc only 

 receptacles; that the cup-shaped disc is biennial, and 

 that this part is truly the plant. From what we have seen, 

 we are disposed to agree with the latter. In September 

 1850, we saw it growing very abundantly towards the 

 close, it would appear, of the first season of its existence at 

 Portstewart, a beautiful place in the north of Ireland. 

 There, at low water, it studded the chtry rocks like olive- 

 green buttons pretty closely congregated. Dr. Harvey, in 

 the second edition of his excellent Manual, says, "From 

 recent observations, I have no doubt that this plant is 

 biennial." The cup-shaped frond, which adheres firmly 

 to the rock, is more than an inch in diameter. The 



