The Midnight bee was developed by crossing the Caucasian and Carniolan stocks, hoping to maintain the extreme gentleness of both strains while removing the excessive propolis of the Caucasians and minimizing the swarming propensity of the Carniolans.
There are also some Black Italian hybrids according to Norman Redpath...
Think you could take a close up pic???
Sounds like you struck it lucky

Ill try and get a close up pic over the next few days, never heard of the midnight bee before.
Had to move that hive to a new site on the weekend as it was the only one i have that is a single all the rest are already 2 or more,
its much easier to move one box in the boot than a double.
I caught a couple in a jar but my camera cant get the closeup detail, the abdomens are pure black along with the rest of the body.