Josie Lyman is the wife of Joseph Lyman, congressman (1885-1889) and lawyer, who practiced in Council Bluffs, Iowa and died there in 1890 (my thanks to Lee at the Sarpy County GenWeb for the info that Josie was actually his wife). She also let me know that they were married July 28, 1869.
To see his congressional biography click here. He’s buried next to her, as you can see from the bottom picture, but with a different type of marker. There are only a few of these rare white lead markers in the cemetery.