15 
species belonging to the Palaearctic fauna. With the genitalia of these 
genotypes the writer is familiar, partly through the drawings of Pierce in 
his excellent, but restricted work on “The Genitalia of the British Noc- 
tuidae,” and partly through the writer’s dissections of specimens pur- 
chased in Europe. In the generic keys to our North American species the 
writer has endeavoured, therefore, to employ these terms correctly, includ- 
ing under each individual head only those species which show an obvious 
similarity of genitalia. This procedure has considerably augmented the 
number of genera employed and in certain cases it has been found necessary 
to create new generic terms. It is quite possible that many workers will 
disagree with this procedure and consider that the groups have been split 
much too finely; as, however, the purpose of the present paper is to em- 
phasize structural differences, rather than similarities, it is hardly felt that 
an apology for this action is necessary; in any case it will be quite easy, 
if so desired, to lump the species again under one generic head, using the 
terms the writer employs in a subgeneric sense. 
STRUCTURAL DETAILS OF AGROTIDS 
Before proceeding with the main scheme of the “Classification of the 
North American Agrotids,” it may be of value to discuss briefly the various 
structural details present in the group and the value of each as a means of 
generic separation. 
Palpi. The vestiture of the second and third palpal joints, notably on 
the under side, shows considerable variability. In a few species, of which 
fennica Tausch. and malefida Gn. are excellent examples, the second joint 
beneath is thickly and evenly scaled; in the majority of species, however, 
there is a fringe of rough hair of varying length and thickness below this 
joint which frequently forms at the apex of the joint a triangular or pointed 
tuft, very characteristic of such genera as Feltia Wlk. and Graphiphora 
Ochs.; this condition Smith has termed “clavate.” In certain groups, 
notably Abagrotis Sin. and its allies, there is a similar, but much less dis- 
tinct, tufting below the apex of the third joint; such a feature crops up in 
a more or less isolated w r ay all through the Agrotids and has been used to 
a considerable extent by Snellen and Hampson as a means of separation 
in their keys; although by no means convinced that in every instance such 
a character is of generic value, the writer has employed it in the present 
paper to a limited extent. 
The length of the third joint, as seen in an undenuded condition, 
seems at times to afford a useful character; generally the joint is short and 
bluntly conical, scarcely longer than broad; in some groups, however, of 
which Anomogyna Staud. is a good example, it is noticeably longer and 
thinner. 
The one requisite in studying palpal vestiture is to have fresh, un- 
rubbed specimens before one for examination and as this is by no means 
always feasible, the general run of specimens being more or less worn, the 
writer has not paid as much attention to the subject as it possibly deserves. 
Snellen, in the paper already mentioned, has illustrated a number of 
palpal types, and a more careful study of our North American species than 
the writer has been able to give along the lines indicated in this article 
might be productive of interesting results. 
66022— 2J 
