I think it matches a bowl that I had recently, (also U.V. reactive) designed by Frantisek Peceny for Hermanova Hut Glassexport (before 1958) seen in the accompanying catalogue CD-Rom to Sklo Union - Art Before Industry: 20th Century Czech Pressed Glass by Marcus Newhall. This shows three versions, two bowls and a shallow one 28cm which I suspect is yours - patt.19805.