It was indeed the Dolphin. Another backwards-stagger-wing. The question was of course inspired by the previous one, thanks dcaponeII.
Not only were there two Lewis guns mounted to shoot over the propeller (sometimes these were reduced to one or none) but there was also an arrangement on some Canadian(?) machines where the guns were mounted above the lower wing, outside the propeller arc (much like the later Gladiator, except the guns for these were mounted in pods below the lower wing).
The top brass, of course, thought that this was going a bit far, and that two guns should be more than enough.
The major issue with the Dolphin was the fear factor (rumour mill, maybe) of the possibility of pilots breaking their neck in the event of a bad landing involving a nose-over (because there was no upper wing to protect him) - hence the "roll bar" on which the Lewis guns were mounted. Maybe this is also why the excellent Bristol M1 didn't find favour on the Western Front (but excelled elsewhere), plus of course, it was deemed to be not as well-built as a biplane.
Over to you.