How can I remove custom shapes from the Lines & Shapes inspector?

I was playing around with OG 4.2.1 (Pro) to see how the Subtract Shapes feature works. (Very nice feature, btw!) I noticed that my newly created shapes were added to the Lines and Shapes inspector. I didn't notice right away, but each test shape was added to the Lines & Shapes inspector. That's great, and I can see how that would be very useful. However, I'd like to remove these test shapes from the inspector.

Is there a way to do this?

Ed