get Property sum total from multiple Classes in List

Hi,
I have a list (i.e. Dim nList as new List(of className)). Each class has 2 properties named propName and propAmount (i.e. className.propName).
I need to get a sum total of the propAmount for each propName.
I can loop through the list with the below but am unsure how to total the propAmount for each propName.
Any advice greatly appreciated.
  For Each receipts1 As className In nList             Next