You posted in the Athleague parish page. Do you have any information that indicates that Richard Murphy came from that parish?
I checked Roots Ireland www.rootsireland.ie and di not locate a baptismal record for a Richard Murphy in Co. Roscommon from 1848-1858. Some churches do not have records back to the early 1850s. Athleague records start in 1808 but there are gaps where records are missing.
Do you have Richard's death record which might show his parents names?