LEONARDIUS LAHILLEI. 
39 
The anal aperture is sheltered by an operculum of a trapezoidal 
shape provided with a lingula which hardly at all, or only a short 
distance, projects beyond the posterior margin of the operculum. 
I can state nothing with precision about the antenna? because in the 
two female specimens which came into my possession they had been 
broken off; from the small remainder still intact it seems to me, how- 
ever, that they are alike in conformation with, or only little dissimilar 
from, the antennae of other species. 
Color of body brown. Length of body a little more than 1.5 mm. ; 
length of forewing 2.250 mm.; width of forewing 1.350 mm.; length 
of hind wing 1.920 mm.; width of hind wing 1.120 mm. 
Length (total) of the first pair of legs 1.660 mm. 
Length (total) of the second pair of legs 1.750 mm. 
coxa 
0. 150 
trochanter 
.10 
femur 
.450 
tibia 
.540 
1st tarsal joint 
2d tarsal joint 
claws 
._ .220 
__ .130 
.070 
coxa 
.150 
trochanter 
femur _ 
__ . 100 
.450 
tibia 
.600 
1st tarsal joint __ 
2d tarsal joint 
claws _ 
__ .230 
__ .130 
.090 
coxa 
. 150 
trochanter 
femur 
__ .100 
.450 
tibia 
.700 
1st tarsal joint— 
2d tarsal joint- 
claws _ 
__ . 300 
__ . 150 
.090 
Length (total) of the third pair of legs 1.940 mm. 
Habitat. — Collected in Argentina upon a plant not classified. 
This insect is found attached to the upper surface of the leaves, in 
colonies more or less numerous, and its presence is readily ascertained 
because of the accumulation of the long dorsal waxy filaments which 
are interlaced amongst each other in all directions, thus forming a 
kind of net whose probable office is the protection of the insects from 
the enemies which infest it. 
On January 18, 1912, Dr. C. W. Hooker sent from Mayaguez, 
Porto Rico, specimens of an aleyrodid taken on Phoradendron, 
parasitic on almond. These insects belong to the genus Leonardius 
herein described. They agree closely with the description of lahillei 
given by Leonardi. Slight differences are, however, noticeable. In 
