Your box was made by Edme Picard, specialist in snuff-boxes (la tabatière), mark EP, a crown and a crescent (une couronne et un croissant) in a lozenge-shaped reserve.
Picard registered this mark 4 times. First on 3 February 1849 when he was working at 114 rue St-Martin; second and third on 16 May 1856 when he was at 186 rue St-Martin; and fourth on 13 June 1860. His last mark was erased on 15 April 1874. Therefore Picard’s working dates were 1849-1874.
See Arminjon, v. II, no. 01541, p. 154.
See also below for more about the history of Picard’s business.viewtopic.php?f=7&t=56652&p=183017&hilit=Picard#p183017