I wondered about the James Lansing name too as well as the Martin Nellis name. Fox was a German Palatine name. I did a quick check on Rootsweb and there doesn't seem to be any Lansings in their background. The only promising clue is that I found a James Lansing married to a Mary Fox about the same time. Christina b:1837 and her younger sister Margaretta b:1849 had another sister, Mary b:1846 but she died in 1859 so that doesn't make sense either. I guess it's a mystery yet to be solved.