In Douglas J. Ingells, The Plane That Changed The World, p. 185, it states:
"They called it the Duck beause it could ...... take off or land neatly on the water". But then it goes on: "The land-water versions of the C-47 were used in Alaska".
This is all accompanied by a pic that shows wheels coming out of the floats but, in my honest opinion, these do represent beaching gear rather than proper landing gear.
Hope this helps.