/list/proc/Cut(Start, End)
Arguments:
Start = 1: Index of the first element to be cut from the list
End = 0: Index past the last element to be cut from the list, or 0 for the last element

Removes the indicated elements from the list.

var/list/L = list(1, 2, 3, 4)
L.Cut(2, 4)

world.log << json_encode(L) // "[1,4]"