Hi and welcome to the GMB.
Your bowl is a Davidson pattern 34SD in Polished Black with snowflake fired-on transfers exclusive to Davidson supplied by Johnson Matthey. Although such bowls may have been sold on their own, most were supplied with a clear crystal 4" No. 3H Dome flower block as a two-piece set. The Polished Black range was launched in 1954. Pattern 34 was launched at the 1934 British Industries Fair.
Information mostly from http://www.cloudglass.com
It's well worth spending some time browsing around Chris & Val Stewart's excellent website.