- The Purdons were active in the affairs of Limerick city but lived in the parish of Ogonnelloe, barony of Tulla Lower, county Clare, from the mid 17th century to the beginning of the 20th century. In the mid 18th century George Purdon married Arabella, daughter and co heir of William Causabon of Carrig, near Mallow, county Cork. Lewis writes in 1837 that, with the exception of 97 acres, the whole parish was in their possession. In the 1850s they held 16 townlands in the parish. George F. Purdon of Tinerana owened 6,298 acres in county Clare in the 1870s. His only son, William Casaubon Purdon, died unmarried in 1893 and the estate was inherited by his two sisters who sold it to the Gleeson family in 1901. A cousin, Reverend William John Purdon of Kingstown, Dublin, held five townlands in each of the parishes of Kilfinaghta and Kilfintinan, barony of Bunratty Lower at the time of Griffith's Valuation. He had two daughters, Emily Jane and Anna Maria. Over 500 acres located in the barony of Clanwilliam, county Limerick, in the possession of Reverend John Head and Simon G. Purdon, were sold in the Encumbered Estates Court in 1853. Mr. McDermott is reported to have purchased the property in trust for over £12,000.
- A Hugenot family who were settled in Youghal, county Cork, by the 1680s. William Causabon married Sarah daughter of Arthur Hyde, Member of Parliament, and bought some of the forfeited estate of Pierce Nagle in the barony of Fermoy in 1703. His son William of Carrig, near Mallow, was High Sheriff of Cork in 1723 and Member of Parliament for Doneraile 1715-1727. He married Arabella daughter of Sir John Rogerson and they also had a son William. The Causabon name also appears in the Purdon and Frend genealogies.