A fairly rare Bryozoan from the Silica Shale at Sylvania is Botryllopora. It is found encrusting shells and other hard surfaces and has a star shaped look to it. Here it's covering part of a Strophodonta shell.
This is a different shell where the Bryozoan has colonized a flipped over Strophodonta shell.
It even grew onto the other side at one point, maybe the shell got flipped again?
This Bryozoan reminds me of a similar looking genera called Constellaria that is found in Ordovician aged rocks.
I'm labeling my specimens Botryllopora socialis based on the 1975 book by Robert V. Kesling & Ruth B. Chilman: Strata and Megafossils of the Middle Devonian Silica Formation: Museum of Paleontology, Papers on Paleontology, No. 8, pg. 62, pl. 18.