This oval tureen and plate measure 9-1/8 x 6 inches and are part of the Cambridge Round line of dinnerware. The bowl and cover have a slot for a ladle or spoon. No triangle c mark, but it has a patent number PAT.71821 on the dish. The silver overlay border etch is unknown and has also been found on a Central candleholder: http://chataboutdg.com/gallery/details.php?image_id=18365