This was sold as a member of the genus Goldius but Sam Gon's www.trilobites.info site states that Goldius is a junior synonym of Scutellum. Ann Archinal in "Zur Morphologie, Systematik, Stratigraphie und Okologie der Gattung Scutellum" ("On the morphology, systematics, stratigraphy and ecology of the genus Scutellum") in Senckenbergiana Lethaea, 74:291-324 describes the species Scutellum pustulatum. It is pretty much a dead ringer for this bug. So either this is S. pustulatum or something very close.

Even though this trilobite has holochroal eyes (a single cornea over all the lenses) the lenses are well preserved and visible under a magnifying macro lens. They are too small to be seen with the naked eye.