Have you ever woken up from a deep sleep with an inspiration? At 3pm this morning I leapt out of bed thinking "Langan", and I'm sure this is right, confirmed by yourself as a possibility. I also found one Fenestry family on
http://griffiths.askaboutireland.ie/gv4/gv_family_search_form.phpThis is an excellent site (posted by a Rootschatter). I'd previously been looking for Corlesses and similar names and had them all in a database. This site gave more than I'd found through the usual searches.
Despite one Fenestry family I'm still not sure about this one unless the family have a foreign origin. It sounds unIrish to me and there is only the one family, perhaps also an error by the census taker.
Unfortunately, I can't post the photocopy of the census.The name is Fenerty but could just be Fenesty.
Any suggestions on Fenerty welcomed!