Not sure if you're still getting replies to this, but here goes... Julius was born Friedrich Wilhelm Julius Belz in Burgheim, Germany, on 13-Sep-1874. He was naturalized in 1904, and his record shows his wife as Fredericka, though in Census records, she was always shown as Emelie or Emily. Not sure if that makes her a 2nd wife, or just that she went by a given vs. a middle name, or vice versa. In any case, the four children were supposedly born in Philadelphia, though Julius appears in 1900 US Census for Camden, but here are their respective birthdates in Philly:

Julius William/Wilhelm Belz b. 17-Jun-1898
Herman A. Belz, b. 28-Sep-1901 (died Oct-1967, NJ)
Anna Marie Belz, b. 06-May-1904
Irvin (Erwin) Carl Belz, b. 11-Sep-1907.

As I'm sure you're aware, Herman married a woman previously married to a Mr. Hetterith/Hetteroth, by whom she had Charles @1920 and Wilson @1921. She had Lois Belz with Herman, b. 1929, NJ.

My friend's line descends through Irvin.