Pholidostrophia nacrea from Arkona

I was introduced to Pholidostrophia last year when I found some in the Wanakah Shale at Lake Erie near the mouth of 18 mile creek. I've blogged about some of those shells here and since then have found some from the Silica Shale in this post and some from the Mahantango formation here. Below is a shell that I found in the fossil gravel I brought back from Arkona last fall.

Based on the locality and overall look of the shell I'm calling this Pholidostrophia nacrea based on this page from the Friends of the UMMP Michigan Basin Image Archive.