Help With a Gastropod

[BobWill]

I found this gastropod at the Lost Creek Dam site near Jacksboro Texas. It's the Finis Shale member of the Graham Formation, Upper Pennsylvanian Period. It has transverse costae which are more closely spaced and angle downward left to right compared to other high spired gastropods found there like Pseudozygopleura  sp. My only resource is the book of index fossils and the closest thing I see there is Hemizyaga sp. but it is not on the fauna list for the site. Scale in mm.