Can anyone tell me the difference between barbarous and barbaric? Is there a time when one makes more sense than the other?

I was grading the NY English Regents today and came across the word "barbarous" in one of the reading passages. It got me a-thinking. The dictionary (Webster's) lists fairly similar definitions for them and they're both adjectives, so I'm curious if there's any difference in meaning or connotation between the two.