8 Introduction 



features, the classification reached after nearly two centuries of 

 study of the adults is confirmed. The phylogeny of the order, 

 relieved of the supposition that all its families must be traceable to 

 a common ancestral type, becomes plainer as the morphology of the 

 larvfe displays the wide gaps between the three suborders Archoste- 

 mata, Adephaga, and Polyphaga. The difficulty of subdividing the 

 Polyphaga on characters drawn from the numi)er of tarsal joints, 

 or the form of the antennae, becomes lessened by the recognition of 

 three types of larvae, leptinid-staphylinoid, cucujoid, and byrrhoid, 

 by means of which the true relationship of heretofore baffling forms 

 may be indicated. 



We congratulate Dr. Boving and his co-workers, F. C. Craig- 

 head, R. A. St. George, and others, in this country and abroad, on 

 the successful outcome of their patient research, aided by the inspir- 

 ing influence and learning of the late Dr. E. A. Schwarz. Even 

 more, perhaps, are the students of the classification of the Coleop- 

 tera to be congratulated on the guidance in their studies afforded 

 by Dr. Boving 's work. The task remains of reconciling the ditfer- 

 ences between the classification of the adults and that of the larvae. 

 In this supplement we are therefore content to indicate, through 

 this introduction, and by footnotes in the text, the alterations in the 

 classification which are probably needed. 



It is a matter of regret that the work of P. de Peyerimhoff on 

 the Larvae of Coleoptera (Annales Soc. Ent. France, 1933) appeared 

 too late for its valuable comments on classification to be noticed in 

 these supplements. 



We thank the many students of North American Coleoptera who 

 have so willingly assisted us in our work, and it is a pleasure to 

 acknowledge for tlie printers, for the publisher, and for ourselves, 

 the assistance of Miss Ethel Olsen, by whom, practically without 

 error, the manuscript was typewritten. 



Charles W. Leng 

 September 1, 1933. Andrew J. Mutchler 



