It looks like pencil. It may well come off if you used a rubber eraser, but, please don't!
My guts feel this bowl might be English or French. I'd go looking towards Jobling or Bagley first...
but the denser pinks around the edges might suggest French. However, pressed glass is not my area - I just have a bit of a thing about good quality, pressed glass, ceiling lampshades. They are really practical.