If you can find out the year of birth of James in Ireland (or close approximation), there is a Civil Registry of Births that will give the names of his parents and the location of birth and exact birth date. The index to the birth registry if available at the LDS Family History Libraries all over the US. From the index, you would get the Birth Registry Volume and Page of the record with its wealth of information.
In addition, there was a Civil Census in Ireland in 1901 and 1911. If he was in Ireland during either of those times, you can find the listing of his family including siblings and ages. If you can get his parents from the Civil Register of Births, you will find the family even if he was born after 1911. Just for information, the Civil Registers of Births, Marriages, and Deaths started about 1864 in Ireland, and are great resources. The Census records prior to 1901 were destroyed by the English and by fire.