Thanks for that, Tom. That was 1912 so they hadn’t been removed before then. Without any evidence to the contrary I would say they are still there.
Cemeteries of The Bronx has a really good writeup on the site including many other things that I did not know. For example, there are two side-by-side vaults within the walled in area. One was used by the Van Cortlandts and the other by the Bayley and Craig families (they were connected to the Van Cortlandts by marriage). One of the monuments for the Bayleys was only just removed by the Parks Dept. a few years ago after it was kicked over. If there are any Van Cortlandts or Bayleys still out there, I wonder how they would feel about the way the city has taken care of their family burial plot.