The 'A' form of our Clan name is in fact very rare, though there are a few examples. The 1776 Religious Survey of Rathlin Island off the coast of Co. Antrim, Northern Ireland, has an 'A' form of a not dissimilar, though in fact unrelated, name, McAhargey. There are two Census examples of the Clan name. In 1851 the County of Antrim, Parish of Newton, Townland of Limavallaghan, lists the following family: David McAlhager, head, 45, Linen Weaver (so born 1806); Mary, wife, 34, winding spools; Eliza, daughter, 24, Linen Weaver (so born 1827); Isabella, son (sic), 16, Linen Weaver; John, son, 6; George, son, 2. Another 19th Century family with the same variant name appears in the 1881 Census in Chertsey, London, England. Benjamin (born 1824) and Mary Ann McAlhager had three children, Frederick B. (born 1877), Florence Mary (born 1880) and Algenon (born 1881).
Finally there are just two instances of the variant MacAlhagga, which I have found on the Internet, both linked with the Scottish Boghall Masonic Lodge, known as Lodge Kirton Hall, No. 1614. Bro. C. MacAlhagga appears in the minutes of its first meeting in 1964 as one of five people appointed to collect subscriptions. Bro. J. MacAlhagga, MM, FM, appears on the Lodge's Memorial Roll. In the Family Tree I have built which contains all the members of the Clan who live in or originate from the Bathgate-Boghall area of West Lothian, there are no obvious candidates to determine who these two men were. Any ideas would be appreciated.