Christopher Belmont rescued his son, Soleiyu Belmont, so I think it would be correct to assume the father son line. Also, Juste Belmont was the grandson of Simon (hair change from red to white?) The only problem with this theory is that Richter was the last Belmont to use the Vampire Killer, until Julius, such a long gap would make one think that Julius is not a direct descendent of the Belmont line. So I would like to see a Belmont PC in the next Castlevania game, the one after Richter, thus making it take place after PoR.