The successful development in recent months of the process of reproducing in colors photographic representations of objects has been to a certain degree the argument for the publication of this book at the present time. A few years ago the preparation of such a work as this at the low price at which it is sold would have been an utter impossibility. "The Butterflies of North America," by W.H. Edwards, published in three volumes, is sold at one hundred and fifty dollars, and, as I know, is sold even at this price below the cost of manufacture. "The Butterflies of New England," by Dr. S.H. Scudder, in three volumes, is sold at seventy-five dollars, and likewise represents at this price only a partial return to the learned author for the money, labor, and time expended upon it. The present volume, while not pretending to vie in any respect with the magnificence of the illustrations contained in these beautiful and costly works, nevertheless presents in recognizable form almost every species figured in them, and in addition a multitude of others, many of which have never before been delineated. So far as possible I have employed, in making the illustrations, the original types from which the author of the species drew his descriptions. This fact will no doubt add greatly to the value of the work, as it will not only serve as a popular guide, but have utility also for the scientific student. I am under obligations to numerous friends and correspondents who have aided me, and take the present opportunity to extend to them all my hearty thanks for the generous manner in which they have assisted me in my pleasant task. I should fail, however, to follow the instincts of a grateful heart did I not render an especial acknowledgment to Mr. W.H. Edwards, of Coalburg, West Virginia, and Dr. Samuel H. Scudder, of Cambridge, Massachusetts. Justly esteemed as the two foremost lepidopterists of America, it is my honor to claim them as personal friends, whose kindness has much aided me in this labor of scientific love which I have undertaken. For the kind permission given me by Dr. Scudder to use various illustrations contained in the "Butterflies of New England" and other works, I am profoundly grateful. I am under obligations to Messrs. Charles Scribner's Sons for permission to use the cuts numbered 46-49, 51-56, 59, 61, 62, and 73, which are taken from the work entitled "Taxidermy and Zoölogical Collecting," by W.T. Hornaday, and to the authorities of the United States National Museum and the heirs of the late Professor C.V. Riley for other illustrations. Should this book find the favor which I have reason to think it deserves, I shall endeavor shortly to follow it by the preparation of a similar work upon the moths of the United States and Canada. OFFICE OF THE CHANCELLOR, W.J.H. WESTERN UNIVERSITY OF PENNSYLVANIA, August 16, 1898. TABLE OF CONTENTS INTRODUCTION CHAP. PAGE