Location: Lansing, New York
So I just got a trilobites of New York book and have been looking to identify some of the many trilobites in the collection in the coming weeks. While I'm not completely positive that this is indeed Phacops rana I have a good feeling that it is. This species is one of the most recognizable trilobites due to their large eyes (in fact the species name P. rana is a reference to the giant eyes of frogs), as well as one of the most common in New York state. This particular specimen was found in Lansing, New York which is part of the Hamilton Group, Moscow Formation which contains fossils from the Middle Devonian Period which started some 416 million years ago. This geologic period is widely noted for the abundant fish, including the armored placoderms such as the fierce dunkleosteus.
UPDATE: This site is actually part of the Hamilton Group, Moscow Formation which includes fossils from the Middle Devonian.