Common Earth-ball Scleroderma citrinum
This globular fungus fruiting body is often seen on the ground, occasionally on rotting stumps,in organically rich woodland.
These look rather young and will become tinted with yellow as they age.
Olympus EM-1, (aperture priority), Olympus 4/3 50mm f2 macro, 1/13 at f8 ISO 1000, hand-held.
The stereo is crosseye.