That looks like the USMC Hospital Corpsman Knife.
The USMC Hospital Corpsman Knife was issued by the Marine Corps during World War II. It was a bolo type knife intended for clearing brush and for cutting wood for litters or shelter poles.
The USMC Hospital Corpsman Knife had an overall length of 16 1/2 inches with a blade that was 11 1/4 x 3 inches. The spoon tip blade was supplied both parkerized or bright. The wooden handle had either three or four flush rivets, steel, iron or brass. The left face of the blade was stamped with "USMC" and the manufacturer identity. (Some genuine knives may not have the USMC marking or the manufacturer name.)
These manufacturers have been identified as makers of the USMC Hospital Corpsman Knife:
•Briddell
•Chatillion
•Clyde Cutlery Co.
•Fayette R. Plumb
•Village Blacksmith
This is a site for infomration only as no items are listed for sale and i have no interest in this site.
http://www.olive-drab.com/od_edged_w..._usmc_hosp.php