WWII EGA ( Marine Corps Eagle, Globe & Anchor ) Model 1937
Most enlisted EGAs were unmarked, yours looks like this one
http://i498.photobucket.com/albums/rr349/Ray1954-photo/post-98-1186260433.jpg
Here's a little history on the Marine Corps Eagle, Globe & Anchor
http://i498.photobucket.com/albums/rr349/Ray1954-photo/icon_blues.gif
Marine Corps Emblem and Seal
The history of the Marine Corps emblem is a story related to the history of the Corps itself. The emblem of today traces its roots to the designs and ornaments of early Continental Marines as well as British Royal Marines. The emblem took its present form in 1868. Before that time many devices, ornaments, and distinguishing marks followed one another as official marks of the Corps.
In 1776, the device consisted of a "foul anchor" of silver or pewter. The foul anchor still forms a part of the emblem today. (A foul anchor is an anchor which has one or more turns of the chain around it). Changes were made in 1798, 1821, and 1824. In 1834 it was prescribed that a brass eagle be worn on the hat, the eagle to measure 3