Samuel J Crossno, (L.J. Crosnow), enlisted in Rieff's Mounted Company, Arkansas State Troops on 5 July 1861, at Camp McRae, AR and discharged 13 Aug 1861 in Springfield, MO. He then, in late August, enlisted in Company 'G', Clark's Regiment (9th MO INF) for the rest of the war.
Commanded by Americus Rieff, it was only in service for about 1 1/2 months. The Company was an independent cavalry troop reporting directly to Brigadier General Ben McCulloch and serving as scouts and the General's escort.
They were discharged right after the Battle of Wilson's Creek.
The original muster roll of Rieff's Company bear's the following endorsment: 'This Company has been in service under me since the first of July, 1861. The Company is now discharged. It has done much valuable service. Ben McCulloch, Brig. Genl. Comdg.'
Many of the Company's soldiers went on to serve in the 34th & 35th Arkansas Infantry Regiments.
Samuel was the brother-in-law to Spear Fort, (15th NW Arkansas), John Gabriel, (4th Arkansas), Isaac (4th Arkansas), and David Hamilton Kuykendall, (24th Arkansas).

Listed as G. A. Malcomb
From the U.S. Parks Service Civil War Soldiers list:
Malcomb , G.A.
BATTLE UNIT NAME:
2nd Regiment, Arkansas Mounted Rifles
SIDE:
Confederacy
COMPANY:
E
SOLDIER'S RANK IN:
Private
SOLDIER'S RANK OUT:
Private
ALTERNATE NAME:
Green A./Malcom
FILM NUMBER:
M376 ROLL 15