I'm no expert, i tried looking on google but i'm not sure. Here's a picture of the D.C. Regina, any expert can tell me ? If this is one of the small beads it's apparently worth over 1000$
A line through the "I" should intersect the middle of a bead to be a small bead; your's does not, ergo: a large bead.
I'm no expert, but that is what seems to be the criteria for determining the difference; as per: 1966 Canadian Dollar question - Coin Community Forum
Don..