Mourning cloak

I spotted a new kind of butterfly today. New to me, I mean. It had creamy yellow-edged wings, a row of iridescent blue spots, and striking dark red-brown velvety main color wings. The best thing is that when I looked it up, I learned that the common name in North America is "mourning cloak" (Nymphalis antiop). I assume the name comes from the plain black underside of the wings, and when the butterfly folds up its wings it's like it's covering itself with a black cloak.