2 Harry Scott Smith 
But little of originality can be claimed for the synoptic tables, — 
most of which are essentially copies of those used by former writ- 
ers, modified and rearranged for the present need; this is espe- 
cially true of the family, subfamily, and generic keys, some of 
which are almost exact copies. These are given principally be- 
cause of a demand for something of the kind for use in the en- 
tomological laboratory of the University of Nebraska. 
The synonymy given is as brief as possible, in most cases only 
the original description and the latest monographic reference or 
the best characterization of the species being cited. Where the 
insect has received more than one specific name or when the sexes 
have been separately described these also are usually referred to. 
The writer wishes to express his deepest gratitude to Professor 
Lawrence Bruner, under whose direction the work was under- 
taken, for valuable advice and encouragement. Thanks are also 
due to Mr. H. L. Viereck for many timely services rendered in 
the comparison of specimens and copying of descriptions which 
were inaccessible, and to Professor H. T. Fernald for like assist- 
ance, while acknowledgments should also be made to Ashmead’s 
Classification of the Entomophilous Wasps of the Superfamily 
Sphegoidea, Fernald’s Chlorioninae of North America, and to 
the many valuable writings of Mr. William J. Fox, all of which 
figured ‘largely in the preparation of the synoptic keys found in 
the following pages. 
Superfamily SPHEGOIDEA 
KEY TO THE FAMILIES 
A. Middle tibiae always with two apical spurs. 
B. Abdomen connected with the thorax by a slender, almost cylin- 
drical petiole; first cubital cell not receiving a recurrent 
nervure; cubital vein in hind wings generally originating 
beyond the transverse median nervure, sometimes inter- 
SHitial oot cb ust wie eur eg a ote tie Soke he Cetera ae SPHECIDAE 
BB. Abdomen not connected with the thorax by a slender, almost 
cylindrical petiole, usually sessile or subsessile; if the first 
segment is petioliform it is not cylindrical, but considerably 
larger in circumference toward apex than at base, rather 
clavate. 
324 
Pe ee es ee ee Cee ee 
