A GENERIC REVISION OF NORTH AMERICAN AGROTID 
MOTHS 
INTRODUCTION 
For several years the writer has been devoting as much time as he 
could spare from other duties to a rather intensive study of the species of 
moths generally known as Agrotids. 1 This has been done with a view to 
determining whether it was possible to secure some better arrangement and 
grouping of the numerous North American species than that proposed by 
Hampson (1903, Cat. Lep. Phal. Brit. Mus., vol. IV) and followed in the 
Barnes and McDunnough Check List , 1917, more or less closely. To most 
students of this group, it has been evident for some time past that the 
associations of our North American species as made by Hampson have in 
many instances been very arbitrary and artificial — species superficially 
very similar have been widely separated and other species very obviously 
dissimilar, both in wing-form and maculation (such for instance as fennica 
Tausch. and oblata Morr. under Agrotis), have been placed close together. 
The group under consideration does not comprise Hampson’s entire 
subfamily Agrotinae, but rather merely the Agrotes of Smith’s revision 
(1890, Bull. 38, U. S. N. M.), for the writer is not at all sure that the 
Heliothid-like forms, associated by Hampson with the true Agrotids on 
account of the spined tibiae, have any very close relationship; in any case 
they are sufficiently distinct to fall outside the scope of the present paper, 
which, roughly speaking, deals with the genera of the 1917 Check List from 
Porosagrotis (page 40) to Protagrotis (page 48) inclusive. 
Following along the lines used in the writer’s revision of the Cleorini 
(1920, Bull. 18, Dept. Agr., Canada) slides have been made of the male 
genitalia of as many of the species of the group as could be obtained, and 
the main groupings have been based largely on the similarity or dissimilar- 
ity of the structure of these organs. The groups thus formed have been 
carefully examined, both individually and comparatively, in regard to their 
further structural characters, especially such ones as have been used by 
Smith and Hampson for generic separation. The writer found that the 
genitalia afford an excellent check on the value of these characters, and has, 
it is believed, definitely proved that certain characters must be dis- 
carded or only used with extreme caution when separating genera. 
The group has always been a very difficult one to divide satisfactorily 
and no two revisers have been able to agree as to how it should best be 
done. Even to the present day in Europe many entomologists place 
practically all the Palaearctic species (which in many respects are very 
closely allied to our Nearctic ones) under the one heading Agrotis, prefer- 
ring a single unwieldy genus to a number of smaller ones (such as we use 
in North America) which do not seem to bring out satisfactorily either the 
generic or the specific affinities of the species involved. Before proceeding, 
1 It has recently been shown by Barnes and Benjamin (Contributions, V, 55, 10231 that the name Phalaeninae 
■will in all probability replace Agrotinae, but in the present paper, for the sake of convenience, the better know* 
designation has been adhered to. 
