He appears to be using the Ponsonby name by 1893 - see this from the Evening Express
Newport Borough Police-court on Friday George Galdos, a ship's steward, was sent to prison for a month for assaulting Arthur Ponsonby, a hairdresser, of Commercial-road, Newport. The prisoner was troublesome, and, on an attempt being made to eject him, fastened his teeth in the calf of one of prosecutor's legs and took a piece of flesh as large as a crown piece out.
Possible previous sighting in 1886 as well