408 
the smaller rootlets liad also been devoured, or more or less injured, 
by them. 
The larva (Fig. IS a) is of a milk-white color, with a prominent black 
head, and attains a length of about G millimeters. Pupation occurs in 
an oval cell lined with a few silken threads, the cells being formed at a 
depth of half an inch or less beneath the surface of the ground. The 
eggs are usually scattered on the ground, but are sometimes deposited 
in clusters of twenty or more; they are oval, polished, white, and meas- 
ure about one-tenth of a millimeter in length. 
This species belongs to the genus Sciara as restricted by the German 
entomologist Rubsaanien in his recent revision of the genera and species 
belonging to this group (Berliner Entomologische Zeitschrift, May, 
1894, pp. 17-24). The present species differs from any of those hereto- 
fore described in several important particulars, notably in the coloring 
of the thorax and pleura: and in the belief that it is as yet undescribed, 
is duly characterized herewith : 
Sciara tritici n. sp. 
Male. — Antennae two-thirds as long as the body, black, the first two joints fulvous; 
head black, the face fulvous; palpi brown. Thorax dorsally fulvous, the pleura 
brownish, marked on the lowest third with a whitish vitta, also with a whitish spot 
below the humerus. Abdomen reddish-brown, basal joints of hypopygium each 
bearing a stout macrochaeta at the tip of its inner side, the apical joints bearing 
several short, claw-like processes on the apical third of the inner side and at the 
tip (Fig. 48). Legs testaceous, front coxae two thirds as long as their femora. 
Wings iridescent, grayish hyaline, the veins brown excepting the fourth which is 
very faint, the forks more distinct but much less robust than the other veins; costal 
and first veins bearing microscopic spines on nearly their whole length, the second 
vein also spinose beyond the small cross-vein, the others bare; costa straight or 
gently convex on the basal half; first veins extending slightly beyond the middle of 
the wing, its last section half as long as the preceding; fourth vein forking far 
beyond the tip of the first, the distance about equaling four times the greatest width 
of the marginal cell; anterior fork of fourth vein seven-ninths as long as the pre- 
ceding section of that vein forking at a distance from its base equal to slightly over 
twice the greatest width of the costal cell. Halteres yellow, the knob brownish. 
Female. — Same as the $ except that the antennae are only half as long as the body. 
The last joint of the ovipositor is slightly longer than wide. 
Length, 1.8 to 2.5 mm . Ten males and fifteen females. 
NOTES ON" PARIS GREEN. 
By C. L. Marlatt. 
Paris green is the most useful and valuable of the arsenicals used as 
insecticides. As is well known, its action is more rapid and effective 
than that of London purple, and having a definite chemical composi- 
tion it ought not to be subject to variation in the amount of the active 
agent, arsenic. Its use as an insecticide has enormously extended of 
late years, and upward of 2,000 tons are annually employed in the 
United States, besides 400 tons in Canada. The chief difficulty in 
