This is the largest of all the families of butterflies, and it is also the most widely distributed. It is represented by species which have their abode in the cold regions of the far North and upon the lofty summits of mountains, where summer reigns for but a few weeks during the year; and it is enormously developed in equatorial lands, including here some of the most gloriously colored species in the butterfly world. But although these insects appear to have attained their most superb development in the tropics, they are more numerous in the temperate regions than other butterflies, and a certain fearlessness, and fondness for the haunts of men, which seems to characterize some of them, has brought them more under the eyes of observers. The literature of poetry and prose which takes account of the life of the butterfly has mainly dealt with forms belonging to this great assemblage of species. In the classification of the brush-footed butterflies various subdivisions have been suggested by learned authors, but the species found in the United States and the countries lying northward upon the continent may be all included in the following six groups, or subfamilies: 1. The _Euploeinoe_, the Euploeids. 2. The _Ithomiinoe_, the Ithomiids. 3. The _Heliconiinoe_, the Heliconians. 4. The _Nymphalinoe_, the Nymphs. 5. The _Satyrinoe_, the Satyrs. 6. The _Libytheinoe_, the Snout-butterflies. The insects belonging to these different subfamilies may be distinguished by the help of the following analytical table, which is based upon that of Professor Comstock, given in his "Manual for the Study of Insects" (p. 396), which in turn is based upon that of Dr. Scudder, in "The Butterflies of New England" (vol. i, p. 115). KEY TO THE SUBFAMILIES OF THE NYMPHALIDÆ OF THE UNITED STATES AND CANADA I. With the veins of the fore wings not greatly swollen at the base. _A._ Antennæ naked. (_a_) Fore wings less than twice as long as broad--_Euploeinoe_. (_b_) Fore wings twice as long as broad and often translucent, the abdomen extending far beyond the inner margin of the hind wings--_Ithomiinoe_. _B._ Antennæ clothed with scales, at least above. (_a_) Fore wings at least twice as long as broad--_Heliconiinoe_. (_b_) Fore wings less than twice as long as broad. 1. Palpi not as long as the thorax--_Nymphalinoe_. 2. Palpi much longer than the thorax--_Libytheinoe_. II. With some of the veins of the fore wings greatly swollen at the base--_Satyrinoe_.