This fossil looks like a modern day millipede. In actuality, it is the Lyriocrinus melissa found in the Waldron Shale of Clark County, Indiana. This crinoid existed in the Middle Silurian Period. Notice the pinnules on the arm section plus the brown color of the fossil. Fossil has not been prepped at all so more of the arm might eventually be exposed.
You can see what an intact Lyriocrinus crinoid looks like visit the Weeks Fossil site link. Now that is a beautiful crinoid calyx!
One day I might post the picture of the calyx fossil this arm belongs to. Still in mourning about the intact fossil being damaged.