FAMILY IV
PAPILIONIDÆ (THE SWALLOWTAILS AND ALLIES)
The butterflies of this family in both sexes are provided with six ambulatory feet. The caterpillars are elongate, and in the genera Papilio and Ornithoptera have osmateria, or protrusive scent-organs, used for purposes of defense.
The chrysalids in all the genera are more or less elongate, attached at the anal extremity, and held in place by a girdle of silk, but they never lie appressed to the surface upon which pupation takes place, as is true in the Erycinidæ and Lycænidæ.
SUBFAMILY PIERINÆ (THE SULPHURS AND WHITES)
"Fly, white butterflies, out to sea, Frail pale wings for the winds to try; Small white wings that we scarce can see Fly. Here and there may a chance-caught eye Note, in a score of you, twain or three Brighter or darker of tinge or dye; Some fly light as a laugh of glee, Some fly soft as a long, low sigh: All to the haven where each would be,— Fly."
Swinburne.
Butterfly.—For the most part medium-sized or small butterflies, white or yellow in color, with dark marginal markings. In many genera the subcostal vein of the fore wing has five, or even in some cases six nervules, and the upper radial is lacking in this wing.