Looks like a heart-shaped framed something in a sliding leather case.

Hmmm....not very clear....the best I can come up with is "a pair of castanets in a fancy carrying case"....but that doesn't seem very "early American" to me...but, like I said, it's pretty blurry!

I picked this book up a few years ago in a used book store.  Great collection of old songs.  Thought I'd post it for the pic of the old dulcimer on the cover.  But can anyone tell me what that thing is on the lower left?