It is a Stevens and Williams fox.
Possibly by John Northwood(the way the paragraph and section is written makes it difficult to tell). Presumably referring John Northwood II although it's not specified in the book.
Source: The Crystal Years by R.S. Williams-Thomas
page 64 and 65
'Leaving small lamp made items and turning our thoughts to animals and birds, we find that John Northwood devotes a page of illustrations in his book to birds and fish, which had been 'still' blown into beautiful details moulds, showing feathers and scales which were subsequently emphasised with the intaglio wheel. Such creatures were chiefly supplied to silversmiths for mounting.
Solid stoppers for spirit decanters were also made in the form
of hounds' heads and foxes' masks.
Lastly there are the little "friggers" made by glassmakers fr their own trading, for visitors and sometimes for sale by the company. These included ....'
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