This very rare small porcelain sucrier or covered sugar bowl is signed in blue underglaze on the base: C D for Coalbrookdale. It was made during the John Rose period of the Coalport company, c.1820-1830. It is about 4" high and 5" wide.
A similar piece, a teapot, is shown on page 285, plate 1210, of "An Anthology of British Teapots" by Miller and Berthoud. It belongs to the Victoria & Albert Museum. Their caption dates it c.1830. The V & A teapot is "attributed to Coalport" and unmarked. Wouldn't it be nice to own a "marked" version of Coalbrookdale?
There is also a photo of the same teapot in the book, "An Illustrated Dictionary of Ceramics", by George Savage. The photo is on page 35, and the caption is: "Porcelain teapot, Coalport, c. 1820. Victoria & Albert Museum, London."
Besides the blue leaves, the main motif of this sugar is the scallop shell, which appears on each side of the bowl. The height is 3-3/4" and the width is about 5-1/8".
The condition of the sugar bowl is good. The head of the bird on the finial of the lid has been replaced. (According to the photos mentioned above, on the similar teapot, it was originally a swan finial.) There are 4 hairline cracks which start on the lip of the bowl. There are various chips to the top edges of the bowl. Nevertheless, this is an exceedingly rare piece which still displays well.