what's this?

[42itous]

It's maybe an inch across -- slightly smaller than the sort of walnut you get at the store. See comments for a picture of the inside.

Comments

[42itous.livejournal.com]

It's a neat little memento mori, and you can see where something (no doubt a squirrel) gnawed on it between the "eyes."

[perspicuity.livejournal.com]

nut?

looks generally like a black walnut

#

[chocorua.livejournal.com]

Could also be a Butternut (also known as 'White Walnut'). Look around for the tree it came from?

[42itous.livejournal.com]

Hmm, an image search suggests that this looks a little more like butternut than black walnut (at least, to my untrained eye). The only trees in the vicinity of where we found this were maples and locusts.