85 
were seen dragging live chinch bugs over the ground, one of 
which barely showed signs of life, a second of which moved its 
legs more vigorously, while a third, which an ant was dragging 
along by the beak, seemed scarcely at all disabled. 
Description (Plate X., Fig. 5 and 6; and Plate XI., Fig. 1). 
Lasius niger and its variety alienus belong to a group of small 
ants, the workers of which are about one sixth of an inch long, 
varying from yellowish brown to dark brown in color, and cov¬ 
ered with a fine dense pubescence intermixed with scattered erect 
hairs, the surface therefore appearing dull or but feebly shining. 
The frontal area is faintly impressed, and the ocelli are indis¬ 
tinct. Their antennae are 12-jointed, the third antennal joint 
shortest, the succeeding joints gradually longer. The maxillary 
palpi are long and slender, six-jointed. Between the base of the 
abdomen and the thorax is a short segment compressed above 
into a flattened vertical brownish scale, not distinctly notched 
above. The anal opening is circular. 
These two forms are very closely related, and the differences 
exhibited do not seem to warrant more than varietal separa¬ 
tion, although some authors treat them as distinct species. In 
typical niger the average size is larger, the color of the female 
and worker is usually darker, and the antennal scape and the 
tibiae bear, among the usual pubescence, scattered, nearly erect, 
hairs, which are not usually apparent in alienus. 
The Grass Root Louse. 
(Scliizoneura panicola, Thos). 
(Plate VIII., Fig. 6; and Plate IX., Fig. 1). 
This species was discovered on the roots of Panicum glabrum 
and other grasses by Mr. H. Pergande, at St. Louis, Mo., in 
November, 1877, and first described by Dr. Thomas, in 1879, 
in the Eighth Report of the State Entomologist of Illinois. The 
first observations of its occurrence in this State on corn were 
made in 1883, and it has been seen by us more or less abund¬ 
ant on the roots of various plants every year during the past 
eleven years. Its economic importance is but small, owing to 
the usually trivial numbers in which it occurs on corn, and the 
evanescent character of its attack. It is often important, how¬ 
ever, that the corn farmer should be a.ble to distinguish it from 
the far more dangerous corn root aphis—a matter of no diffi- 
i culty to a fairly good observer. It may be told at once from 
that species by its white or yellowish color, and by the absence 
of the projecting cornicles or honey-tubes characteristic of Aphis, 
these being replaced in the present species by a pair of minute 
circular openings on the hinder part of the back, each delicately 
rimmed with brown, and surrounded by a small dark patch. 
