Bergamia prima (Elles,1940).
Fine well preserved complete Trinucleid. Both positive and negative halves. Nice detail under magnification. With a Graptolite lying next to it.
Ordovician, Uppermost Llanvirn Series,'Llandeilian' Stage, Llanfawr Mudstone Formation.
Maesgwynne, near Builth Wells, Powys, Wales.
Trilobite : 1.2 cm long.
