There are two varieties for the Canada 50 cents 1978
1978 KM#75.3 (smaller bust, 2mm planchet, round beads)
1978 3,341,892 KM#75.3 (smaller bust, 2mm planchet, square beads)
When we talk about "beads" we automatically think about the circle of beads alongside the rim, but these have nothing to do with this variety. The variety here is the shape (round of square) of the jewelry at the base of the crown, as you can see on the pictures here: http://www.coinsandcanada.com/coins-prices.php?coin=50-cents-1978&years=50-cents-1965-2015
