NYC Naturalization Record Index 1791-1992

I am trying to find the detail of the Naturalization records for Edward Flavin. On Ancestry they show a number of 65098 and it is filed in the US District Court of Southern District of NY. Edward was born in 1848 in Ireland and died in 1888 in NYC which give me an idea of when this claim was filed. Can anyone tell me where to search for the actual documents? My name is Sharon Pizzuti and I am searching my Flavin lineage.