Finding Dory maintained its spot at No. 1 for the third week in a row this July 4th, taking in $50.2 million at the four-day weekend box office.The Pixar-Disney fish tale kept reeling viewers in, making for a total of $380.5 million so far--just $300,000 shy of matching the entire run of its predecessor, Finding Nemo. Finding Dory outperformed its competition, including The Legend of Tarzan, which finished second at $45.6 million. The Purge: Election Year came in third with $34.8 million.The BFG, Steven Spielberg's adaptation of the Roald Dahl children's book, came in fourth, taking in a paltry $22.3 million in its opening weekend. It's proving to be a big disappointment for the Hollywood icon, as experts now doubt The BFG will recoup anywhere close to its $140 million budget, and are hoping foreign markets will prevent it from becoming a disaster.Independence Day: Resurgence rounded out the top five with $19.3 million.