The White-faced Darter is a small (33-37mm) dark dragonfly, superficially
similar to the Black Darter with a pale creamy white frons. One of our
rarest dragonflies, they are restricted to a few local sites in England
and Scotland. The furthest site south is Chartley Moss - a private reserve
managed by English Nature.
There is also a successful reintroduction program underway in Cumbria. Temperature extremes may be the reason why they're not found further south, although they were present at Thursley Common in Surrey until relatively recently.