empty case

empty case

Observation - empty case - UK and Ireland. Description: Found on moor(Grassyish, sometimes grazed by sheep. Fairly damp at times. mm ruler used. It feels to have no weight. It was large open end up when I found it.To the touch it 'feels' and sounds crisp! I have never seen anything like it before! (I have it i

Found on moor(Grassyish, sometimes grazed by sheep. Fairly damp at times. mm ruler used. It feels to have no weight. It was large open end up when I found it.To the touch it 'feels' and sounds crisp! I have never seen anything like it before! (I have it in box in house.)3 pics attached