I may have accidentally discovered the cemetery, or at least where it was located. A 1900 deed conveying land from Mary Ann Peacock, granddaughter of James Towler, to the City of Xenia, mentions a family grave yard in the deed. She is conveying land (Parcel ID 40000100310000100) "reserving the right to a family grave yard as reserved in fromer [sic] (former?) years. In the deed she mentions James Towler died in 1836.
Another 1900 deed from Robert Stewart to the City of Xenia also mentions the cemetery. "Excepting and reserving therefrom all the part of said land which has been inclosed within a brick wall for a cemetry or burying ground, and also six feet in width on all sides of said burying ground necessary from the outside of said brick wall, and also a path way to the same six feet in width running from said ground N 52 1/2 degrees E. 8 poles and 20 links to the aforesaid Rail Road. Containing in all Ten Hundredths of an Acre of land." You can enter the Parcel ID at http://www.co.greene.oh.us/gisMap/http://www.co.greene.oh.us/gisMap/ and it will bring up the location of the parcel.
The parcel was once the city dump after the bodies had been removed to Woodland Cemetery.