almost certainly Sowerby - it matches with the number of fingers, and those two small side by side diamonds lower down the bowl section, were a Sowerby decorative feature on many of their 'fingered' bowl shaped pieces.
This design seems to have started out in the early 1930's with some variation in shape, and were called Table Centres, with frogs and plinths -although as salad bowls they don't appear until some time in the 1940's - and again you could have a plinth. The pattern No. for the salad bowl was 2505 - fingers could point either up or down.
Need to see this piece side on to get an idea of the depth and see if it matches the shapes in the CD catalogue - the size of which is quoted as 9". It was offered in blue, and if you look in Miller's /McConnell '20th Century Glass' - page 65 you'll see the sort of blue and an example of the 'Table Centre' range offered by the factory. Your particular shape is not shown, unfortunately, and your pic. seems to show a much paler blue than was usual for Sowerby