I believe this is him, although, the initials do not match. See:
http://files.usgwarchives.net/ga/military/civilwar/rosters/3rdreserve.txt

W M. Darby

Enlisted as a Private
"D" Co. GA 3rd Reserves Infantry (Served as a guard at Andersonville Prison)
Sources used by Historical Data Systems, Inc.:
- Index to Compiled Confederate Military Service Records
- Research by Jack Lundquist

..........

W. M. Darby, Private, Company D, 3rd Regiment Georgia Reserves, enlisted April 20, 1864 at Oglethorpe, Georgia by Captain Thomas P.S. Loyd for the war, last recorded present on the Sept & Oct, 1864 muster roll where they were stationed at Camp Lawton, on the previous bi-monthly muster they were stationed at Andersonville

M266: Compiled Service Records of Confederate Soldiers Who Served in Organizations from the State of Georgia

.........

J J. Easterling
Enlisted as a Private
"H" Co. GA 5th Cavalry