very pretty - is the surface decoration formed by blowing it out causing the crackles rather than it being an acid etched decoration maybe? can't remember the details but some Walsh glass has this effect near the rim I think .
I looked up Walsh and came across an iridescent blue bowl marked Walsh England, but the description says "typical wide ground pontil" whereas this is unmarked and has a small ground pontil mark.
During a google search last week I came across Fenton stretch glass bowls where the iridescence is applied first and there are 'stretch marks' in the iridescence as the glass has expanded. Checked for that on the bowl and it's not one of those.
The etched surface looks like acid has been sprayed on the top half of the outer surface and has run down the sides of the bowl, leaving smaller holes and lines on the upper half and longer lines on the lower half. It hasn't eaten into the iridescence so that must have been applied afterwards.
The foot hasn't been etched or iridised so it must have been applied last.