This is a rare Encrinurid trilobite. Nearly all of the few "complete" specimens found are molts. This is the only specimen I've seen for sale that is complete, with free cheeks attached. Each free cheek on this trilobite is small, consisting of the optical surface of an eye and a thin sliver of shell below that. So there isn't a lot of difference between molts and complete specimens with this species.

The trilobite shares its plate with a Favosites coral, a bryozoan, and some small brachiopods -- typical Silurian seafloor bric-a-brac.

Most molts I've seen of this species are about 2.5 cm long, this specimen with attached free cheeks is about 2 cm long. This is the common trade off between size and quality.