Hi Jerry,
The name Malarkey is comparitively rare in Fermanagh around the time you are interested in. The Tithe Rolls of 1834 list three:
Owen in the townland of Drumbarry, parish of Galloon
Pat in the townland of Cessiagh (Culliagh), Parish of Cleenish
Thomas in the the townland of Caranaculla (Carrowmaculla), Parish of Galloon.
In 1848 there was also a widow Malarkey in Enniskillen who was granted outdoor relief during the Great Famine. In the Griffith Valuation of 1862 the name appears to be recorded as McLarkin.
Regards