Welcome to the GMB.
Nice clear photos, by the way.
Definitely Davidson, and an unregistered design.
Not a pattern that I have come across before, but the style and the demi-lion mark points to 1880-1890.
The nearest pattern that I can see in the Davidson catalogues for that 1880-1890 period is Davidson covered sugar #171 (apart from the fact the bowl of the sugar in the catalogue illustration seems to have an unflared plain top). – the stem and foot look very similar, and the alternating bands of vertical and horizontal ribbing on the bowl seem to match.
The ‘sugars and creams’ section of the catalogue often shows an uncovered version of the sugar plus a matching creamer, but in this case there is no corresponding illustration to verify the identification.
Fred.