This is an excellent example of an extremely uncommon trilobite. It is a beautiful Illaenus insignis from the Rochester Shale. This is not the much-more-common Bumastus ioxus, although they look similar - Illaenus insignis is probably the third rarest trilobite from the Middleport Quarry. This specimen is complete, which is only one of a handful of this type ever found complete with free cheeks. The trilobite is also nicely outstretched and very well articulated, which is also quite uncommon. The distinct bug displays beautifully and is well showcased in the center of the plate of shale. This is a very collectible example of this extremely rare Silurian trilobite from New York State.