branch which appears to be a continuation of it. But from the origin 
of the first marginal branch, the vein is greatly attenuated and is de¬ 
flected towards the middle of the wing, and subdivides into two branches 
opposite the point at which the first marginal branch attains the costa. 
The two branches into which the subcostal divides are delivered one to 
the costa just behind the tip and the other midway between this and 
the costal end of the first marginal branch. The median vein is two- 
branched and is well defined from the base to its branches, all of which 
are attenuated. The posterior branch is short, and the next is deliv¬ 
ered to the tip of the wing and receive an oblique discal vein from the 
last branch of the subcostal, which closes the disk. The submedian 
vein is simple. 
Head smooth, with oppressed scales. Ocelli—? Antennae one-third 
less long than the fore wings. Labial palpi slender, ascending, not 
higher than the vertex; the second joint is scaly, the third smooth. 
Beneath the labial palpi are small, ascending maxillary palpi. Tongue 
naked, as long as the fore coxa and femora. 
The larva is much flattened, and the segments separated by deep in¬ 
cisions particularly on the sides. The head is extremely thin, circular, 
with a peculiar appendage in front of the mandibles, similar to that 
found in the larva of Lithocolletis of the second group^ which it like¬ 
wise resembles in form. Like these it has three feet and three abdom¬ 
inal prolegs and one terminal pair, all very short. It leaves its mine 
at maturity to weave a white, semi-transparent cocoon within some cre¬ 
vice of the bark of the tree on which it feeds or upon the ground. 
The exterior of the cocoon is covered with little froth-like globules, 
which resemble minute pearls. 
The imago rests with the front part of the body elevated, and I be¬ 
lieve, the fore feet applied to the breast, like the members of the ge¬ 
nus Tischeria. The antennae are held extended at the side of the 
head, and have a constant trembling motion. 
M. salictella.—Fore wings dark fuscous, with a silvery-white band at the 
basal third of the wing, and a slightly oblique one of the same hue, in the mid¬ 
dle, inclined towards the inner angle. ITear the tip of the wing is a dorsal and 
costal silvery-white spot opposite each other. Behind the dorsal spot, is a nar¬ 
row, somewhat curved white streak, extending from the apical cilia to the mid¬ 
dle of the wing. Cilia silvery-grayish at the tips. Hind wings grayish-fuscous. 
Antennae grayish-fuscous. Head silvery-white. Labial palpi silvery; the 
hairs of the second joint touched with fuscous. Maxillary palpi dark fuscous. 
The larva mines the young branches of the yellow willow tree. I 
