PORTHCAWL, SOUTH WALES.—On the morning of the 12th April, about low water, the barque Marmora, of Copenhagen, Copenhagen, bound from Rochfort to Porthcawl, drifted on the Skerweather Sands. The Ohafyn Grove Life-boat was immediately launched and rescued the crew of eight men from the vessel, over which a heavy ground sea was dashing; she had been dismasted, and eventually became a total wreck. All hands must have been lost in the absence of the Lifeboat..