VARIETIES
Sometimes the individuals of a species differ in different parts of the country; these different forms are called varieties, and are designated by a varietal name added to the generic and specific names. Papilio turnus, Linn. is a large yellow swallowtail, but in the southern part of its range some of the females are black. The black female was formerly regarded as a distinct species, and Linnaeus named it Papilio glaucus, but when it was reared from eggs laid by a yellow female it was recognized as a variety, and is now known as Papilio turnus, Linn., var. glaucus.
CHAPTER VI
THE FOUR FAMILIES
As we said in the chapter on Classification, American butterflies fall naturally into four great groups called families: the Nymphalidae or Four-footed family, the Lycaenidae or Gossamer-winged family, the Papilionidae or Swallowtail family, and the Hesperiidae or Skipper family.