resturgeon on Family Tree Circles

Researching my surname of Sturgeon.
At a stone wall. I have gone strait back to 1777 but can't get across the big pond. Have several clues, but nothing for sure.
I have a book entitled "The Sturgeons of North America". published in the 1920s. This book goes back to Ireland and makes a lot of suppositions that are claimed as fact, tosses out some completely, but it goes back to late 1600s.
I know that the Sturgeon family were Norman and came to England with William the Conquerer. They were lords in Suffolk County, but by the 1500s they were living in the Scottland lowlands and were in the "plantations", known as Ulster Scotts or Scotts Irish. They migratred to America from there.
I would like to find links from Ireland back to Scotland.