These WWII USMC P42 camouflage pants are part of the P 42 camo uniform that was used by the Marines during World War Two.  The P42 uniform consisted of a camouflage shirt and pants made out of a herringbone twill fabric.  The uniform is reversible.  It has a green/jungle pattern camouflage on one side and a brown/beach colored camouflage on the other.  The P42 uniform was later replaced by another camouflage uniform, the P44 uniform.  Although the P44 uniform was made out of the same camouflage HBT material, the P44 was cut differently.

This particular pair of P42 pants are a nice original pair showing some period use and wear.