Mr. F. Walker’s Descriptions of Aphides. 45 
feelers is about half the length of the fifth ; the seventh is about 
thrice the length of the sixth : the rib-vem begins to widen soon 
after the middle of the length of the wing, and emits the fourth 
vein near its tip ; the third vein 1s forked a little before one-third 
of its length, and forked again just after two-thirds of its length. 
Length of the body a line ; of the wings 23-3 Imes. 
69. Aphis trirhoda, n.s. 
This species, which has a very quiet disposition, abounds on 
the rose in the spring, and having acquired wings in May, it 
emigrates thence to the columbine, where it feeds equally on the 
upper surface and on the under surface of the leaf, which often 
becomes red or purple from its injuries. It continues on that 
plant till the end of October. 
The viviparous wingless female. It is elliptic, slightly convex, 
not shining, whitish green, covered with a white bloom, and re- 
markable for the peculiar softness and velvety appearance of its 
skin: the front is straight: the feelers are white, and about half 
the length of the body; the first and the second joints are not 
angular ; the fourth is less than half the length of the third; the 
fifth is shorter than the fourth; the sixth is much shorter than 
the fifth ; the seventh equals the fifth in length : the eyes are dark 
brown: the mouth is white with a brown tip, and hardly reaches 
the middle hips: the tip of the abdomen and the nectaries are 
white, and the latter are one-twenticth of the length of the body : 
the legs also are white. 
Ist var. Pale yellowish green. 
2nd var.? ora distinct species. The body is elliptical, convex, 
dull, grass-green, with a very slight white bloom : the feelers are 
brownish green, and about one-fifth of the length of the body : 
the eyes are black: the mouth is dull green with a black tip, 
and does not reach more than half way between the fore and the 
middle legs: the nectaries do not rise above the surface of the 
body : the legs are dark brownish green, and rather short. 
The viviparous winged female. This unfolds its wings at the 
end of May: it is pale greenish yellow: the head and the discs 
of the fore-chest, of ‘the middle-chest and of the middle- 
breast are black : there is a large black spot on each side of the 
middle-chest : some short confluent black bands form a large 
irregular spot on the disc of the abdomen, on each side of which 
there is a row of black dots: the feelers are black, and a little 
shorter than the body : the mouth is pale yellow ; its tip and the 
eyes are black: the nectaries are pale yellow, and one-twentieth 
of the length of the body; the third joint is rather stout; the 
fourth is very slender, and less than half the length of the third ; 
the fifth is a little Bence than the fourth, ne the sixth flan 
