Elza is not listed in my book, period - he's not in the index.The book does have a tiny Walls Cemetery in Lynn Twp and here is the listing:
Walls Cemetery (all names listed as "Wall") (Big Creek)
Wall, Rebecca, wife of James, died 18 Dec 1852 Wall, Inf. dau. of James & Rebecca, aged 6 da. Wall, Mary, dau of James and Rebecca, age 9 da. No Name Given - foot stone says T.W. No Name Given - foot stone says M.W.
In April I purchased a book called Posey County Death Records, volume 3 (I only have 1 of the 7 books).There is this listing, don't know if it's the same person you are looking for.The name is indexed as Eliza but it is a man.
Walls, Eliza 26 male white. Date of death Jan. 18, 1884. Occupation farmer. Born Indiana died Point Twp. Cause of death pneumonia. Father William Walls born Ohio.Mother Ellen Moulder born Indiana. Date of return Jan. 18, 1884. There are several other Walls names in the book too including Alvin, James, Frank, Willie (mostly children)