Aulacopleura konincki (Barrande).
Small piece of grey siltstone. On the upper surface is a perfect articulated little Proetid trilobite with the original white exoskeleton. Both eye and both librigenes still attached. Very cute.
Silurian, Wenlock Series, Motol Formation.
Lodenice, Czech Republic.
Trilobite : 8 cm. long.