He may have been confused with Oramel, son of Elijah, son of Elijah
The ages given for Ormel G. Barnum's wife and children are based on the 1850 Census record.
In the 1850 Census for Gouverneur, Saint Lawrence County, New York the family of Oramel G. Barnum was enumerated as follows;
Household #435; Family #449
Ormel G. Barnum, 33, M, Farmer, b. New York
Harty F. Barnum, 28, F, b. New York
Florilla C. Barnum, 11, F, b. New York, Attended school within the year
Florence Barnum, 8, F, b. New York, Attended school within the year
1860 Census, Gouverneur, Saint Lawrence County, New York, Page 708, Household 277-317
Barnum, Ormell G., 42, Farmer, New York
Barnum, Harty F., 37, New York
Barnum, Florence, 17, New York
1870 Census, Gouverneur, Saint Lawrence County, New York, Page 272a, Household 213-417
Barnum, Ormel G., 53, Farmer, $5000, $700, New York
Barnum, Harty F., 48, Keeping house, New York
1880 Census, Gouverneur, Saint Lawrence County, New York, Page 427b
Barnum, Ormel, head, 63, Farmer, New York, Vermont, Vermont
Barnum, Hasty, wife, 58, Keeping house, New York, New York, Vermont
Lyon, Maud, granddaughter, 16, At home, New York, New York, New York
Barnum, Daisy, granddaughter, 9, New York, New York, New York
Ansky, Almira, mother-in-law, 81, Vermont, Vermont, Vermont