McCauleyIrish, Scottish Anglicized form of Gaelic Mac Amhalghaidh or Mac Amhalghadha meaning "son of Amhalghaidh". The given name Amhalghaidh, from Old Irish Amalgaid, is of uncertain meaning.
McCulloughIrish Anglicized form of Irish Mac Cú Uladh meaning "son of Cú Uladh". The byname Cú Uladh means "hound of Ulster". This surname has also been associated with Old Irish cullach "boar".
McDermottIrish Anglicized form of Irish Mac Diarmada meaning "son of Diarmaid". The McDermotts were nobility in the Kingdom of Connaught, a province in Ireland.
McDevittIrish Anglicized form of Irish Mac Daibhéid meaning "son of Dáibhí".
Mendel 2German Derived from a diminutive of the given name Meino. A famous bearer was Gregor Mendel (1822-1884), a Czech monk and scientist who did experiments in genetics.