A second and more detailed photo of the modiolopsis slab. This one shows a little bit more detail, hopefully.
Also, it appears that this thing is not full of modiolopsis as I first concluded, but rather it is full of Whiteavesia pholadiformis. There is also a Cymatonota lenoir, and it appears to me that there is only one specimen of modiolopsis, which would be M. concentrica. Dime shown for scale, and Georgian Bay formation, Mimico creek.