In the Unwrap editor, the Select menu has a tool for this. http://help.autodesk.com/view/3DSMAX/2017/ENU/?guid=GUID-2AEF6A44-859D-434E-8E08-00D2A480A0CD
http://web.archive.org/web/20041109084645/http://dynamic.gamespy.com/~polycount/ubb/Forum2/HTML/001740.html?012-200104162142 oh they're still there just not as blatant
Looking at the example you provided and as you are in max 2017 - just click with shift held down at the start edge and drag to the end edge, man :smile: