This is a 19th century Scottish burr root  snuff box. This  Scottish  snuff box  is carved from burr root wood from a huge old tree, having a hinged cover. The lid depicts a scene from ‘Tam O'’Shanter. 
It measures approx 8cm w x  5.5cm d x 4.5cm h.
Burrs  occur on many trees, most commonly at the junction of the trunk with the ground or root.  
They are caused by a number of small shoots which are unable to break out, and form an interwoven, contorted but unusually stable mass. They can be very ornamental.