45 
It is not claimed that this list of localities is by any means com¬ 
plete, as it is made up from my own collection and some two or three 
brief lists which are at hand. It is more than probable that most of 
the species found in New York will also be found in Illinois. For 
the benefit of the entomological students of Illinois who may desire 
to determine species, and in order to enable those injured by Plusias 
to know the guilty species, I give here descriptions of species known 
to be found in Illinois, and of a few others which will probably be 
discovered here. 
Pl. aerea, Guen. 
Front wings triangular, very sharp at the apex, which is falcate; 
outer border gibbous a little behind the middle; the inner border 
straight in the middle portion, but suddenly curved at the anal angle, 
forming a kind of tooth; of a deep violet brown, with an irregular, 
darker line running from the anal angle to the apex; about three 
partial and somewhat confused lines of the same color and parallel to 
the first, most distinct on the inner half; the anal angles often with 
a saffron tint or luster. Posterior wings paler, of an almost uniform 
ocher-gray, with a faint coppery or golden luster. Underside of all 
the wings with a strong brassy luster, the disk of the front pair dark, 
the borders light; fringe pale. The head and prothorax heavily 
covered with saffron yellow hairs; the thoracic tuft with the anterior 
portion more or less yellowish, rest dark or pale brown. Abdomen 
pale, irridescent. Expansion of the wings 1.35 to 1.45 inches. 
This species is without the silvery marks on the front wings so 
common in this genus. Is found throughout the state. 
Pl. balluca, Guen. 
Front wings very acute at the apex and strongly falcate; of a silken, 
yellowish gray; the median and subterminal spaces, with the exception 
of the cellule, of a brilliant greenish yellow or pale olive color; the 
space next the base of a more silvery shade. The two oblique trans¬ 
verse lines which separate the spaces, very slender, brown; the inner 
separates distinctly the two spaces, it curves in passing through the 
cellule, and is straight, but oblique, from the nerve to the posterior 
or inner margin. The middle space is without the usual metallic spots. 
The posterior wings of a clear, uniform, silvery gray, without mark¬ 
ings; their underside of a clear, pale, uniform shining yellow. Under¬ 
side of the anterior wings with a slight purplish shade. Head and 
prothorax honey yellow; rest of the thorax gray; tufts of the abdomen 
usually sprinkled with yellow. Expanse 1.80 to 1.90 inches. 
Hubner figures the posterior wings with a black lunule, but the 
specimen before me is without this.mark, and Guenee says it was also 
wanting in his specimen. 
Pl. aereoides, Grote. » 
Front wings with the apex somewhat acute and slightly falcate; 
general color yellowish brown, with a fuscous shade across the inner 
