Sliding shell package for smoking articles

Smoking articles, such as filter cigarettes, are packaged in a metal box which is curved to a shape that conforms to the curvature of the human body so that the box can be comfortably carried in a shirt or pant pocket. The metal box comprises a lid and a four sided tray. The lid and the tray have rolled lips which interengage to mechanically and slidably retain the lid to the tray. The lid covers the open front of the tray and is slidable along an arcuate path corresponding to the radius of curvature of the lid to selectively open or close the front of the tray. The lid of the box includes an abutment that prevents the lid of the box from being completely removed unless additional force is applied to push the abutment past the rear wall of the tray.