254 Mr. F. Walker^s Descriptiuns 0 / Aphides. 
of the sycamore. The eggs are spindle-shaped, and very large in 
proportion to the size of the mother ; when newly laid they are 
pale, but they soon become black and shining, and have much 
resemblance in size, shape and colour to the eggs of most other 
species of Aphis. I have not seen more than twelve eggs in the 
body of a single insect, and the number is usually much less ; the 
egg lies lengthwise along the body, and by preserving the Aphides 
in Canada balsam the process of its formation is seen, and it may 
be ascertained to be homogeneous, and not a mere envelope for the 
young Aphis, as some authors have conjectured. An egg some- 
times occurs in the fore-chest, but its presence there is probably 
accidental. 
The winged male. Unfolds its wings in the beginning of Oc- 
tober ; it is darker than the winged female, and has more nume- 
rous marks on the chest and on the abdomen, and its wing-brands 
are also of a darker colour. It is brownish yellow : the head, the 
disc of the chest, and that of the breast are brown : the head is a 
little broader than the chest : the abdomen is brown and linear, and 
has a broad pearly whitish green stripe on each side : the feelers 
are thick tow^ards the base, and longer than the body : the nec- 
taries are dull pale yellow, brown at the base, and as long as one- 
fourth of the body : the thighs except the base, and especially the 
hind-thighs, are somewUat darker than the shanks. In the fore- 
wing of one fly the lower vein of the first fork, instead of pro- 
ceeding to the hind-border of the wing, curves backwards and 
joins the second vein at a short distance from its tip. It pairs 
with the wingless female from the middle till the end of October. 
1st variety. Black in such parts where this sex is usually 
brown. 
In this species, as in other Aphides, the union of the branch- 
veins with the rib-vein is usually more or less imperfect, and this 
variableness occurs even in the opposite wings of one fly, but the 
junction is in some cases fully effected. The seventh joint of the 
feelers has occasionally but little more than half its usual length. 
Length of the body 2 lines ; of the wdngs 4 lines. 
2. Aphis Acerinay n. s. 
I observed this insect near London from the beginning of July 
till the end of October 1847, feeding on the leaves of tw'o young 
sycamore-trees {Acer Pseudo-plataniis) that w^ere about five feet 
high, and were situate a mile apart from each other, one in a 
garden, the other in a w'ood. It is a very lively, active and 
elegant s])ecies. 
The viviparous winged female. Its body is of a bright lemon- 
colour ; the feelers are yellow, and very much longer than the 
body ; the tips of their joints arc brown ; the third joint is very 
