The central vase shaped splat with a carved shell on a further shell and the very nice detail of a carved volute on each side of the splat. To each side, the uprights follow the shape of the splat and connect with the shepherd's crook arms. The chair has a drop in seat upholstered in green silk velvet, framed by a serpentine front seat rail carved with a shell and foliage and supported on cabriole legs carved with 'C' scrolls foliage to the knees and claw and ball feet.

English, Circa 1735

Reference
For an almost identical chair.
English Furniture from Charles II to George II By Symonds. Fig 96 page 122

Old English & Walnut Furniture RW Symonds plate xix

Masterpieces of English Furniture & Clocks Fig 3.