Info...please

[Jimmypop]

I sometimes find these things in a garden where I find many artifacts. Some are drilled, others are not. The drilled ones are smooth on the outside. The others are rough on the outside. What could they be used for? If they are some kind of artifact, what age group would have used them?

 

[Tentwing]

Jimmy pop,
Hard to tell from the picture , but those look like chrinoid stems to me.

Tentwing