Taken on 30th May 2008, Lincoln UK. They are very small at 3.5-4.5mm in length. Larvae are known to mine clover leaves, this was near clover on my drive.
If you look carefully you will see stripes on the eyes.
This species is quite black all over. There is another common, similar species C. aeneum which has yellowish legs, yellow tinted wings and is greenish-black.