My original answer regarding :nth-of-type is simply wrong. Thanks to Paul for pointing this out.
The word "type" there refers only to the "element type" (like div). It turns out that the selectors div.bar:nth-of-type(2) and div:nth-of-type(2).bar mean the same thing. Both select elements that [a] are the second div of their parent, and [b] have class bar.
So the only pure CSS solution left that I'm aware of, if you want to select all elements of a certain selector except the first, is the general sibling selector:
.bar ~ .bar
http://www.w3schools.com/cssref/sel_gen_sibling.asp
My original (wrong) answer follows:
With the arrival of CSS3, there is another option. It may not have been available when the question was first asked:
.bar:nth-of-type(2)
http://www.w3schools.com/cssref/sel_nth-of-type.asp
This selects the second element that satisfies the .bar selector.
If you want the second and last of a specific kind of element (or all of them except the first), the general sibling selector would also work fine:
.bar ~ .bar
http://www.w3schools.com/cssref/sel_gen_sibling.asp
It's shorter. But of course, we don't like to duplicate code, right? :-)