IOWA ACADEMY OF SCIENCES. 
197 
The examination of several hundred examples embracing 
some twenty species at present referred to five different genera 
and including all of the above mentioned variations compel the 
rejection of the cross nervure as an absolute character, or one 
capable of even specific recognition, except as correlated with 
other characters, and the re-establishment of the Burmeisteran 
genus based on head characters. It may be noted, however, 
that when thus restricted, it contains no species lacking the 
cross nervure nor any in which it is found to be variable. 
The material upon which the revision has been based, and 
which has been accumulating during a number of years past, 
consists mainly of the following: Types of the ten VanDuzee 
species; types or typical specimens of all but two of the Gillette 
and Baker species, together with a series of several hundred 
Colorado specimens, received through the kindness of Professor 
Gillette. Twenty European species of the genus as defined by 
Melichar, more than half of them direct from him, which, in 
connection with his recent synopsis, furnish a good basis for 
comparison of the American and European faunae. The Van 
Duzee material in the genus outside of the types, which, 
together with them, includes all but one of the eighteen 
described species which he listed in his catalogue. And, lastly, 
the college collections of thousands of specimens of adults and 
larvae, together with a large series of balsam mounts of larvae, 
elytra and wings, structural details and dissected genitalia for 
microscopic examination. These, embracing twenty- five spe- 
cies, among them the one lacking from the VanDuzee material, 
and thus complete the series of described American species. 
After restricting the genus it was found that it could be sep- 
arated into three well defined groups, each of which has its 
parallel in the European fauna. In fact, two out of the three 
groups possess species common to both continents. The first, 
or reflexed veined group includes species with short pronotum 
and sharp margined head; the elytra have little or no appendix 
and the costal veinlets are white- marked, strongly reflexed in 
one series and nearly right-angled in another. Of this group 
Mlineatus represents one extreme and is closely related to the 
European formosus, while ocellaris common to both continents, 
and sayi closely related to the European and socialise repre- 
sents the other. They agree in being of a general light brown 
color with definite markings, and are two-brooded as far as 
known. The larvae are light, with four brown stripes. The 
