ID please

[Koopyetz]

Found on western side of Canandaigua lake, fingerlakes region of New York.

Thank you

[Kane]

These look very similar (to my eye) to Stophodonta ?demissa. Let me tag a few others: @Tidgy's Dad , @Jeffrey P

[Koopyetz]

6 hours ago, Kane said:

These look very similar (to my eye) to Stophodonta ?demissa. Let me tag a few others: @Tidgy's Dad , @Jeffrey P

Thank you for helping with answer.

[abyssunder]

I can't help you in the ID, but it looks the one of your specimens has beekite coat (forming a ring). 

 

 

 

[Tidgy's Dad]

Megastrophia concava, methinks.