194 CEABACE^. 



2. MT. opaca Ag. 



Lakes, and ponds— frequent. Fl. July. 

 Down — Lakes at Loughinisland, BalljTiahinch, and Clandeboye ; S.A.S. 

 Antrim -Marsh at Whitehead, and plentiful in the ponds and lakelets of 



Rathlin; S.A S. 

 Deny— In Co. Derry ; IF. Thompson, 



