It just so happens that my family and I were there today (Thursday, the 5th of July) but we observed only 3 grave markers. As you say, Jeremiah, James (Jas) on the head stone and a bowl shapped marker between the two of them, but we could see no inscription on this Bowl type marker. I determined that it may be James' wife, or perhaps a child, but, as I say, no inscripion could be observed.
Michael O'Brian Sr.