The problem with mosses is that it's very difficult to show them well in photographs. I was going to take a photo through the microscope but it didn't come out well and wouldn't be that instructive. This is a moss collected growing on the site of a WWI sea-plane hangar at Newhaven. (Well it's not the actual moss but the same species.) This time keying it out was a bit simpler - Creeping Feather-moss, Amblystegium serpens. It's very common and usually found on living or dead wood, but also on soil and stones, the bases of walls and tarmac.