Scutum
From MiddleWiki
A Scutum is a type of shield with a center boss best known for its use by Roman Legions.
According to Webster's Dictionary a scutum is "an oblong shield made of boards or wickerwork covered with leather, with sometimes an iron rim; carried chiefly by the heavy-armed infantry."
External Links
Wikipedia article on the Scutum sheild: http://en.wikipedia.org/wiki/Scutum_%28shield%29
