Pochette or Violon de poche - meaning pocket in French. There is a famous Baroque-era violin used by "dance masters" called a pochette or a kit - an almost direct descendent of the Middle Eastern rebec. A passable description & some good photos click here. Usually their sound is quite small and a little strident.
Stradivarius even made one at least. (I bet his kit makes a good sound.) I saw a Stradivarius Pochette in the Musee de la Musique in Paris a few summers ago!