All of the Euploeinæ are "protected" insects, being by nature provided with secretions which are distasteful to birds and predaceous insects. These acrid secretions are probably due to the character of the plants upon which the caterpillars feed, for many of them eat plants which are more or less rank, and some of them even poisonous to the higher orders of animals. Enjoying on this account immunity from attack, they have all, in the process of time, been mimicked by species in other genera which have not the same immunity. This protective resemblance is well illustrated in Plate VII. The three upper figures in the plate represent, as we have seen, species of the genus _Anosia_; the two lower figures represent two species of the genus _Basilarchia_. Fig. 4 is the male of _B. disippus_, a very common species in the northern United States, which mimicks the Monarch. Fig. 5 represents the same sex of _B. hulstii_, a species which is found in Arizona, and there flies in company with the Queen, and its variety, _A. strigosa_, which latter it more nearly resembles. SUBFAMILY ITHOMIINÆ (THE LONG-WINGS) "There be Insects with little hornes proaking out before their eyes, but weak and tender they be, and good for nothing; as the Butterflies."--PLINY, PHILEMON HOLLAND'S Translation. _Butterfly._--This subfamily is composed for the most part of species of moderate size, though a few are quite large. The fore wings are invariably greatly lengthened and are generally at least twice as long as broad. The hind wings are relatively small, rounded, and without tails. The wings in many of the genera are transparent. The extremity of the abdomen in both sexes extends far beyond the margin of the hind wings, but in the female not so much as in the male. The antennæ are not clothed with scales, and are very long and slender, with the club also long and slender, gradually thickening to the tip, which is often drooping. The fore legs are greatly atrophied in the males, the tibia and tarsi in this sex being reduced to a minute knob-like appendage, but being more strongly developed in the females. The life-history of none of the species reputed to be found in our fauna has been carefully worked out. The larvæ are smooth, covered in most genera with longitudinal rows of conical prominences.