The butterflies of the District of Columbia and vicinity

The area covered in this report includes the District of Columbia, Arlington County, and the portions of Alexandria, and Fairfax County, Va., immediately adjacent, the Potomac River Valley as far as Great Falls, and the territory east and north of Washington as far as the Eastern Branch, Beltsville, Paint Branch, Silver Spring, and Chevy Chase Maryland. It was necessary thus to extend the limits of the area because of the obliteration within the District itself of various types of habitats presumably once supporting butterflies that are now no longer found within its borders.