Lost ID for this gastropod

[RJB]

Hi all.   Just found this gastropod in a box for my collection and realized that the tag with all the info is gone.  Sad to say.  I found this along the Vanduzen River about 20 miles from where it empty's into the Eel river.  I cant even recall the Formation.  I think its one of the Wildcat group Formations?  I do remember that I dontated one to a fella who worked for the Natural History Museum of LA.  Any help would be appreciated.  Thank you

 

RB

[FossilDAWG]

Very nice!  I suspect @MikeR will be able to help.

 

Don

[hemipristis]

nice gastropod