Museum Exhibit Question

[Noriko]

My boyfriend and I live in Boston so we were fortunate enough to see the Samurai exhibit at the MFA. However, there was a collection of items in the exhibit that we were very curious about. Next to an absolutely gigantic bow, there was a collection of arrow heads. Unlike the points on the arrows in the quiver next to it, these were almost spade shaped pieces with sort of punch cut decorations that were very large, almost the size of a child's hand. Would anyone be willing to give a bit more detail? The exhibit just said they were arrowheads. Given their size, it's very curious...

[Saionji Shonagon]

If they looked too large and/or too decorative, they were likely used as gifts or votive offerings.
www.ncjsc.org/gloss_yanone.htm has some nice examples of Japanese arrowheads of various types. I have a small yanone pendant which looks very much like the bottom-most yanagi-ba example on that page.