Hi, Harry and Everyone Else!

Well, I found the dratted shell, and I discovered that I have at least one other smaller shell of the same specie.   The distinguishing feature is not the yellow on the exterior, but
on the inside under the hinge, there is a short yellow streak
perpenicular to a line through the hinge; and this streak is bounded on each side with a purplish streak.   I should know
this specie, but the name temporarily eludes me.    Anyone
care to help?

Cheers,
Linda