Family of Lars Hartvig Larsen,Drammen,Norway

Hi, this is my first attempt on this forum and and I hope someone can help me find information or point me in the right direction. I found Lars in the 1900 census for Drammen. He was born in 1883 in Frogner Sogn, Lier. If my translation is correct he was an apprentice printer. I found him again in the Ellis Island records arriving in New York January 26th 1908 on the ship Arabic from Liverpool. I know this was him because the address he gave as going to is the address of his wife's sister and brother-in law. The puzzle is that he is listed on the passenger list as single when in fact he had a wife Anna Prunkl(German-Hungarian) and a son, Lars Ferdinand Larsen, who was born 12th July 1907 in Austria on the way to America. I can find no record of Anna and the baby until the 1910 census for Philadelphia Pennsylvania. If anyone can help me figure this out I would be very grateful.