i take it thats its a concave pontil, i have a few P/Ps bowls same shape with stripes in same colourway, have to look them out and take pics to post, they are very similar, ive been away from Ysart glass for around 4 to 6 years, cant really remember now, seem to have got the bug again in the last few weeks, i used to be more into my lamps and unusal pieces but sold about 35 lamps over the last three years mostly private, ranging from tulips to mushrooms and pedestal lamps, still have around 20 i suppose that ive kept with a few rare examples, might look them out sometime and take some pics,