Pridhamsleigh is certainly hypogenic, Holwell probably is, and Baker's Pit may well have hypogenic elements, but also modification due to sediment input (paragenesis) and epigenic cave development. There are lots of other hypogenic caves in the UK, notably the Pennine maze caves, the Derbyshire vein cavities and similar cavities in North Wales, the Yorkshire 'guelphs', Pen Park Hole & some of the isolated chambers in west Mendip (Denny's Hole and sites on Axbridge Hill), and others. There is active research into hypogene speleogenesis in the UK, and Alexander Klimchouck from Ukraine is currently seconded to Manchester University. Do you have any calcite mineralisation (large calcite crystals) in the voids like in Pen Park Hole? I hope that you guys will write up the exploration and speleogenesis of your site for Cave & Karst Science; you have clearly made many good observations, - and photos. Keep up the good work...