From your post today on Irish immigrants to Wales thread:
Hi
I'm completely stuck with my Connolly/Connellys that originated from bandon, Co Cork and settled in Merthyr Tydfil. They moved sometime to Wales after 1881 but before 1891. I am looking for Patrick and Catherine Connolly b 1846, with children of Edward b1872 in Bandon, Daniel b 1874, Mary b 1877 and Ptrick b1880, all in Ireland. I have written to the Monsignier of Bandon parish and although Edward states in later census Bandon was his birth place there are no records of any of the childrens births/basptisms nor the marriage of Patrick and Ellen 
IGI shows good match for this family but it's possible the details you have aren't correct if your only sources of ages are census records.
Patrick Connelly m. Catherine Reilly. Children:
1. Edmund born 21 Feb.1870 Co. Cork
2. Daniel born 16 Aug.1872 Co. Cork
3. Patrick born 27 Nov.1879 Cork, Co. Cork
Note: not all Irish births are in IGI so there could be other children born in Ireland.
Civil registration of Catholic marriages in Ireland started in 1864. See LDS pilot site for index to Irish civil registrations:
http://pilot.familysearch.org/recordsearch/start.html#p=2;t=searchable;c=1408347You need to find a marriage for a Patrick Connelly and then a marriage for a Catherine Reilly (spellings may vary) where the date, registration district, page and volume numbers match up.
As regards to Irish names, Edmund and Edward seem to be interchangeable even in more recent times.