The backs are different. One is a more basic back with "Lacrosse Series" and crossed sticks at the top. The other is more ornate and has "Lacrosse Series" at the top and "Leading Players in the Canadian National Game" at the bottom. Can't remember off the top of my head which is which but I can post tomorrow if no one does in the meantime.
Each series has approx 100 cards but again going by memory and it's late!