sentences:  To the existing parliamentary borough were added some additional parts of the parish of Aberdare, part of the parishes of Merthyr and "Faenor" (Vaynor), and part of the district of Mountain Ash.The same boundaries were retained in 1885, and can be seen on the boundary commissioners' map.Merthyr Tydfil saw one of the most remarkable contests of the 1868 general election.