Such a fabulous and gorgeously  patinated sauce boat with the sweetest design of swallows and flowers designed by Creil et Montereau. Dating from the 1880s,  it is the Naples design, also stamped 'Terre de Fer' French for Ironstone. The detailing of the design is beautiful.
 
The design is a soft teal, green with a tint of blue. It has the expected gently accumulated staining and light crazing one would expect from a well used ironstone piece of this age. Notably the lid has a lighter patina as the warmth of the sauce has caused the depth of the patination in the bowl.
 
The saucière measures 6" tall and 12" long