Jack,
I have Collinses out of Lissane/Tooreen (the Humphreys) and McCarthy-Sowney out of Lissane. That's my Granddad's side.
My Grandmom's Collinses were out of Cullomane East (just west of Drimoleague), and before that Adrigole at the north end of Castlehaven parish. Daniel Collins married Mary Mahony. Odd thing is, the Mahonys who showed up for that wedding and sponsored the Cullomane Collins children were the same names that showed up in a branch of the Humphreys in Lissane. In Lissane, there is a Denis Collins = Margaret Mahony marriage.
Mahony names: Denis, Timothy, Daniel, Kean(Cain), Catherine or Kate. I suspect they were from Bredagh and am about to ask Skibbereen Heritage to investigate.
I have other McCarthys probably out of Garryglass, Drinagh.
My Cahalane is probably out of Kilmacabea parish.
Please let me know if you think we have anything in common.