In 1870-72, John Marius Wilson's Imperial Gazetteer of England and Wales described Carrog like this:
LLANDDEINOL, a parish in Aberystwith district, Cardigan: on the coast, 6 miles S by E of Aberystwith r. station. Post town, Aberystwith. Acres, 2,077; of which 80 are water. Real property, £1,442. Pop., 260. Houses, 46. The property is divided among a few. The parish was formerly called Carog. The living is a p. curacy in the diocese of St. David's. Valne, £66. Patrons, R. Price, Esq. and Capt. Vaughan. The church is good, and contains an octagonal font.
A Vision of Britain through Time includes a large library of local statistics for administrative units. For the best overall sense of how the area containing Carrog has changed, please see our redistricted information for the modern district of Ceredigion. More detailed statistical data are available under Units and statistics, which includes both administrative units covering Carrog and units named after it.
GB Historical GIS / University of Portsmouth, History of Carrog, in Ceredigion and Cardiganshire | Map and description, A Vision of Britain through Time.
Date accessed: 25th October 2014
Click here for more detailed advice on finding places within A Vision of Britain through Time, and maybe some references to other places called "Carrog".