Odd Tomb

There is a photo on the Forgotten New York website, of a very strange tomb in Evergreen Cemetery.

http://forgotten-ny.com/2014/10/forgottentour-86-evergreens-cemetery
It looks like a cylinder, with a conical top, possibly stone.

Can anybody tell me about this odd thing?

I Googled the cemetery, and one of the image results led me to this walking tour - most of the comments seem to be about that mausoleum.

One person says:

This BillionGraves.com entry seems to corroborate that it’s W.H. Guild’s burial spot.

My thanks.