magoito beach, portugal

animals areas atlantic beach biology calcite conoidal das environs european fauna flat gastropod geological gibbula hand interstitial invertebrate iodine joao lampa lampas life lines lisbon low macro magoito marine mollusk nature ocean overcast pebble pools portugal rich ridges rock rocky rosered roundish sao sea season seawalled shell shore significance sintra small snail snails solid species spiral spots steromphala striped sublittoral summer teromphala thick tide top trochidae umbilicalis waters waves