This shuttle from a Vesta Machine is a hybrid between the Transverse or Boat Shuttle, and the Vibrating Shuttle.
It operates from side to side in a straight line like a conventional Transverse Shuttle rather than the front to rear arc of the Vibrating Shuttle, and has the same shape, but the bobbin is fully and loosely enclosed like a Vibrating Shuttle.
Vesta call this a "Cylinder Shuttle", but this is different from the Cylindrical Shuttle produced by the Jones Company which was essentially an improvement on Singer's Vibrating Shuttle.