Jason,
Any part the 40th Mississippi played in the action at Davis Bridge was small. Green's (Hebert's) Division arrived late in the action. They deployed about 1/2 a mile east of the Hatchie River and assisted Maury's Division which was falling back in good order. Green's 4th Brigade (Martin/McLain)was engaged with the Union 4th Division under Hurlbut but only for a brief period of time. There is no indication the 2nd Brigade (Colbert) which included the 40th MS was engaged.
Tom