Between St. John's water dog and the Polish Hunting Dog which was known to be a landrace bred for a specific purpose? 
St. John's water dog: The St. John's water dog, also known as the St. John’s dog or the lesser Newfoundland, was a landrace (a dog bred for a purpose, not pedigree or appearance) of domestic dog from Newfoundland. Polish Hunting Dog: The Polish Hunting Dog, or formerly Polish Scenthound (Polish: "Gończy Polski" ) is a breed of scent hound originating in Poland.
St. John's water dog