This is a rare trilobite double. It is a wonderful pair of Flexicalymene retrorsa from Ohio. Although Flexicalymene is not a rare trilobite, natural doubles are very uncommon. Both trilobites are nicely outstretched and have both free cheeks intact, which is extremely rare. The bugs are actually touching and are nicely showcased on the large block of shale. This is a very collectible pair of outstretched Flexies from Ohio.