The Great Purple Hair-streak is a beautiful, iridescent blue creature, as seen from above, with blackish borders around the blue. As seen from below, the wings are dark brown, with red spots near the body. The two tail-like projections are quite long. It is very large for the group to which it belongs, measuring nearly two inches across the expanded wings. It is a tropical form, extending into our southern borders from California to Florida and occasionally occurring north as far as southern Illinois. The larvae feed on oak. (_See plate, page 256._) =The White-M Hair-streak= _Eupsyche M-album_ The White-M Hair-streak is about two thirds the size of the Great Purple species with less blue and more black on the upper wing surface. The hind tail is slender and well developed, and the angle of the wing just back of it is rounded out in an unusual fashion. The lower surface of the wing is of a general grayish brown color, marked by a white stripe, which takes the form of the letter M: hence its name. This is also a southern species occurring at times as far north as Ohio and even Atlantic City, New Jersey. The caterpillars feed upon the leaves of oak and Astragalus or milk vetch. There is also a third species of this group of whose history we are ignorant except for Abbot's observations. It is an exquisite little butterfly called the Least Purple Hair-streak (_Calycopis cecrops_) and is apparently a tropical form which has spread into our Southern states. It is especially beautiful because of the brilliant red and white lines running across the under surface of both wings. It occurs as far north as West Virginia and Kentucky and ranges westward at least to the Mississippi Valley. =The Gray Hair-streak= _Uranotes melinus_ This exquisite little creature is capable of surviving under a great variety of climatic conditions. It ranges from New Hampshire to Florida and Central America, but apparently occurs only rarely north of the United States. Perhaps the most distinctive feature in the female is the orange spot just in front of a pair of tiny tails on each hind wing, the rear one being curiously curved and about three times as long as the other. In the male the shorter tail is absent. The general color of the upper surface is a dark bluish gray, relieved on the margin of each hind wing by a few white dots and the orange spot already mentioned. The under surface is much lighter gray, distinctly marked with two dark brown lines near the margin, the outer line little more than a row of spots and the inner line with a white edge. (_See plate, page 257._)