I thought it might be Galway trying to lure you into their zone (like a mermaid onto the rocks) so that they could hit you with their (rather extraordinary) VFR transit charge!
Actually all controlled airspace in the Republic of Ireland is class C (bar some area where light aircraft rarely venture which is class A). We don't have any class D.
mccourtm's post did confuse me given his location and the class D reference
but he's clarified that now
and if anything the zone has been extended to the extremes of your exercise turning points.
As much as they would like to, I don't believe ATC have the authority to extend the coverage of their control zone as and when they feel like it
As to the original question, I sometimes get a similar thing at my home airfield (Dublin) when arriving back from a cross country.....told to report a point inside the zone when I'm outside and haven't been explicitly cleared in. If it's obvious to me that the clearance is implicit, then I usually preface my read back with "Understand cleared into the zone at xxxx report............." . At this point the ATC'er usually clarifies and confirms that I am cleared into the zone.
If there is any doubt in my mind at all, then I take IO540's approach and directly ask if I am actually cleared into the zone at this point.
dp