Mourning Cloak. The photograph is of a page in the New International Encyclopedia.
Author New International Encyclopedia
Source: https://commons.wikimedia.org/wiki/File:NIEdot132.jpg

Nymphalis antiopa, known as the mourning cloak in North America and the Camberwell beauty in Britain, is a large butterfly native to Eurasia and North America. The immature form of this species is sometimes known as the spiny elm caterpillar. Other older names for this species include grand surprise and white petticoat.