Hi,
yes, its a circlotron.
The load is connected between the two cathodes of the output tubes.
As such the output impedance is lowish, allowing for transformer-less drive of a attached load, though it seems to be preferable to galvanically isolate the load with an output transformer.
Circlotrons also seem to cope quite well with electrostatic speakers as load.
Besides the requirement for two floating power supplies the driver stages need to be beefier than with conventional amplifier designs since they need to provide for the full voltage stroke.
regards
Calvin