According to the Nature Conservation, the snails most likely arrived on their grounds more than 100 years ago on stones imported from Italy and Greece. Since then the snails have only populated a small area, but the Nature Conservation is conducting a search to see if the snails have populated anywhere else. They are asking the public to be on the look out for the snail.
One quote from the article actually makes it sound as if finding the snails outside of their natural territory is a good thing: "The Victorians and Edwardians loved importing statues, rock, and brickwork from the Mediterranean," says Mr. Oates. "The shipping over of this 'bling' in large quantities suggests that we could find new species, such as this lovely little snail, in surprising places."