360 New York State Agricultural Society. 
■which follow, which gradually but very slightly decrease in thickness to the three 
last, which are enlarged into the knob, and are more broad than long, the last joint 
being hemispheric and with the convex sido outward. The thorax is more wide 
than long, scarcely wider across its base than its apex, convex above, and on each 
side abruptly depressed into a thin outer edge, which is much widened at the base, 
the basal angles being rectangular. The scutel is small, square, and rounded on its 
hind side. The wing covers are scarcely broader than the thorax, and have slightly 
elevated slender lines running lengthwise. The legs are of medium size, the hind 
pair longest, the thighs thick and stout and slightly narrowed at each end, the shanks 
gradually thicker toward their tips. The feet are more slender, their soles with 
dense fine hairs. They are five-jointed, the middle joints very small, the fourth joint 
minute and concealed between the lobes of the third joint; the last joint longest, 
equaling all the preceding joints in length, with a pair of small hooks at its end 
which are strongly curved and furnished with a prominent tooth at their base. 
Lettuce Earth-louse, Rhizobius Lactucm, new species. (Iiomoptera. 
Apliidse.) 
On the roots of lettuce, often in,great numbers; very small oval, white and pale- 
yellow lice, with dusky legs and antennae, their bodies dusted over with a white 
powder. 
The roots of the lettuce in our gardens are much infested by small 
white wingless lice, which begin to appear upon them early in the 
season, and multiply and become extremely numerous toward its close. 
When the lettuce is becoming too advanced to be longer useful for 
the table, and is beginning to shoot up to seed, upon uprooting it to 
clear the ground it occupies for other uses, the lumps of earth which 
break from around its rootlets will frequently be observed to be pro¬ 
fusely pervaded with what appears to the eye to be a white moldiness. 
But on examining this white substance with a magnifying glass, it is 
found to be a white flocculent matter — a dry mealy powder — inter¬ 
spersed with short white down-like threads. And upon the slender 
rootlets of the lettuce will here and there be seen a small white louse, 
with its body dusted over with the same white powder, showing that 
the moldy appearance of the earth, which was first noticed, has been 
produced by these lice crawling through it and rubbing off a portion 
of the mealy coating of their bodies. 
And when one of these plants is uprooted, on breaking off pieces 
of the ball of earth adhering to the roots and rootlets, cavities will be 
come to which are filled and crowded with a swarm of these lice, of 
all sizes, from the newly born infants to the full grown adult females, 
promiscuously heaped together in a confused mass, their bodies dusted 
over with the white mealy powder above mentioned, and the hind ends 
of many of them, and the backs also in some, coated with short floc¬ 
culent fibres, giving them an appearance of being dressed with minute 
