1915] Distribution of Neuropteroid Insects 3%) 
phoride, Megacilissa, Exomalopsis, Entechuia, A piomerus, Con- 
orhinus, Anasa, Zelus, Polybia, Schistocerca, Volucella, Schinia. 
I doubt not but there are other elements also in our fauna, 
but I think that these are the most noticeable, and sufficient to 
show that the Nearctic insect fauna is not a realm, but a con- 
glomeration of several such realms. 
The history of each insect is written in its structure. It is 
therefore possible to discover where each form arose and how it 
accomplished its distribution. This involves a study of the 
phylogeny of the genus or family, an investigation of its orig- 
inal home, and the causes that have aided or barred its dispersal; 
but the essential basis of all is the systematic study of the group 
