Another Unusual Coin from the Trau Collection

I have just come across another unusual coin of the London mint that was offered for sale and illustrated in the Trau auction catalogue of 1935. This coin has the obverse abdication bust of Diocletian usually associated with the PROVIDENTIA DEORVM QUIES AVGG reverse types of RIC VI 76 and 77 but has a simple GENIO POPVLI ROMANI reverse. Probably an early case of London getting the die pairs mixed up but an interesting coin, none the less.