This is a 685 sugar bowl shown with a lid in the 1874 catalogue P40. Whether this one had a lid originally I'm not sure, there isn't any wear around the fire-polished rim or anywhere. It has quite a few uranium colourant seeds. Diameter is 5", height 4 1/2", and the density comes out at 2.75g./cm2.
http://www.victorianpressedglass.com/pdf/sowerby/sowerby_1874.pdf