Cornulites proprius on a Platystoma Fossil

Pictured are several Silurian Waldron Shale fossils. It appears to be the fossilized habitat of a Cornulites proprius attached to the gastropod Platyostoma niagarense. This ensemble was found in Clark County, Indiana. While snail/worm fossil combos are found quite a bit in the Shelby County, Indiana, my experience is they are not quite as common in the more southern county of Clark in Indiana.

Fossils have not been prepped yet so I am hoping for better detail once they are cleaned.