Mat like as name suggests growing on Caliblepharis alga - mid shore.
No interactions present.
One of the pictures, Graham, is no longer showing.
I now have a microscope (so never go to bed!). I am investigating Electra pilosa at this very moment and these have the elongated cells which are quite irregularly arranged but with an additional small cell at one end, from which a single stalk emerges.
Take a look here https://docs.google.com/file/d/0ByoxPfmErX6jNnpZeWVIa0RhS2s/edit?usp=sha...
Lat/Lng: 51.3833, 1.3184
OS grid ref: TR310701