We have therefore in these separated districts two apparently good species, answering to any definition of that name. But between, there is a belt of latitude passing through New York and southern New England, where in one section or other both types are found and the whole series of intergrades. In this belt _Alope_ and _Nephele_ are found to be dimorphic forms of one and the same species. I formerly was of the opinion that they were distinct species, though in some districts there were intergrades. I thought these approaches of one to the other did not bridge the whole space between. In a paper printed in Proc. Ent. Soc. Phil, 1866, I gave my reasons therefor. But some observations made in July, 1876, at Martha’s Vineyard, led me to suspect a closer relationship between the two species or forms. In the open country back of Oak Bluffs, I found these butterflies fresh from chrysalis, and in considerable numbers. They were all very black, diminutive, and there was every grade from what I had been in the habit of calling _Nephele_ to unquestionable _Alope_, with a broad clear-colored band. The band was not yellow, however, as in the typical _Alope_, but reddish-yellow like that of _Pegala_, which Fabricius called _rufa_ in distinction from _flava_, applied to _Alope_. Mr. Scudder took the same small reddish-banded form on Nantucket, which island is about 30 miles from the mainland, Martha’s Vineyard being about 7. I call this variety _Maritima_, but whether it is restricted to the islands, or appears on the adjacent coast, I am not yet advised. Mr. Mead obtained for me a large number of eggs of this butterfly, while at the Bluffs shortly after my departure. They were laid by the broad-banded females in confinement and mailed to Coalburgh. There the larvæ hatched out, and these as well as the eggs were found to be precisely like the same stages of _Nephele_ from Catskills. But none of the larvæ survived the winter. In the belt spoken of, _Nephele_ rather keeps to the highlands. It is the prevailing form in the Catskills, if with it are classed the intergrades, but full-banded _Alope_ may be taken in small numbers every season. Along the Hudson River, _Alope_ is the common form, but I have received intergrades very near to _Nephele_ from Mr. Hulst, taken at Hoboken, N. J.; and a black _Nephele_ ♂ from Mr. H. Laitloff, which he writes me was taken some five years since near Greenville, Jersey City. It was so unusual a form that Mr. Laitloff sent it to me for name. At Coalburgh, W. Va., _Nephele_ is never seen, but _Alope_ is the only form; and so on southward.