Have a look at my public tree Josephine Salt Family Tree 09.06.2012.
There is a Crowley McCarthy marriage in fairly recent times & you will find that the Crowley family is also linked to General Michael Collins in fact I think run the small museum in Co. Cork. Use www.genealogy.i.e
to find info but you will need to know place of birth/baptism as the surnames are the same all over Co. Cork and if you go far enough back are all related to each other.
My McCarthy family came from & some still live in Garralacka, Co. Cork - for them you look in Rossaleteri on the Irish site I have just give you.
Good luck :-D