This is a wonderful specimen of Isotelus mafritzi from the Ordovician of Canada. The extremely symmetrical trilobite is almost perfectly prone and beautifully articulated. The specimen is somewhat inflated and exhibits great detail. The trilobite shows hardly any ''crushing'' which is very unusual. The eyes protrude above the sleek carapace, and the short genal spines are easily seen. The black trilobite contrasts nicely with the gray matrix. The ancient arthropod is well centered on the rectangular plate of limestone. This is a striking example of this ''classic'' trilobite.