91 
black pigment, but usually of good size. The posterior tuber¬ 
cle is distinct, and bears three equidistant oval lenses radiat¬ 
ing from the apex of the tubercle. Rudimentary ocelli sometimes 
visible. 
The prothorax bears above an irregular oblique spot, with dark 
outline, on each side of the disk. Dark lines, in line with these 
spots, lie on each side in the transverse thoracic sutures, becoming 
double posteriorly, and from these a double row of small spots 
continues to the tip of the abdomen, sometimes obscured by the 
discal markings of the segments. The four segments behind the 
head are almost entirely fuscous, except on the suture and at 
the sides of the first abdominal segment. The three or four seg¬ 
ments preceding the cauda are yellowish fuscous except near the 
lateral margin. The other abdominal segments show 7 faint mot¬ 
tled fuscous bands. The cornicles are very distinctly indicated 
by fine dark rings nearly level with the surface, surrounded by a 
dark blotch. Cauda very short, subtriangular, not projecting, 
it and the anal plate yellowish fuscous, hairy. 
Beneath slightly paler than above, with markings of similar 
color; legs and beak brownish yellow. The beak attains the 
base of the abdomen, last two joints dark brownish yellow, 
tip black. The basal two joints are together about twice as 
long as the third and fourth combined. The third joint is 
slightly broader than the others, about as long as broad; the 
fourth joint is half longer, pale-ringed just before the tip. Legs 
nearly smooth, femora darker apically, tibiae paler except at 
base and apex, claws dark, large. The abdomen has a marginal 
row 7 of dark blotches, in which are situated the spiracles, and 
above these, a large subcircular excretory pore on segments 1-4 
and 7. A similar large oval pore lies just below the lateral 
margin of the prothorax. These are homologous with the tuber¬ 
cles of the corn root louse, and perhaps with the cornicles also. 
Below the spiracles is a row of dark spots in the sutures. The 
seventh segment bears the usual transverse oblong brownish 
yellow plate. 
Length 1.5 mm., breadth .9 mm., antenna .5 mm. 
Described from numerous specimens from roots of grass and 
corn. 
The young show the usual differences of size and color, and 
proportionate greater length of appendages. The antennae have 
but five joints, the third proportionally shorter. 
Pupa.—Oval, more elongate, yellowish white, head and thorax 
dusky, no distinct markings except the double row of spots. 
Antennae about attaining base of posterior wing-pads, with su¬ 
ture between III and XV imperfect. Wing-pads attaining middle 
of second segment beneath, posterior pair pale, turned down¬ 
ward more than the anterior, which are brownish dusky. Plate 
of seventh segment beneath indistinctly marked. Tip of ab¬ 
domen hairv. 
