Middlemass
Middlemass is originally a Scottish surname with a number of variants.
In his reference work "The Surnames of Scotland", George F Black includes the surnames Middlemas, Middlemass and Middlemiss as one and identifies the source of the name as an area around Kelso, Roxburghshire in the Eastern Borders of Scotland and specifically a place Middlemestlands. Further variations Midlemas and Middlemist appear in "A dictionary of English Surnames" by P H Reaney [subsequently revised by M A Wilson] where those authors also indicate the Scottish source of the surname.