1.10 
ti 
*3 
hi 
r 
p 
3 
medium length. Antennae and body smooth. Wings usually very 
thin and delicate, the veins sometimes margined with fuscous, some¬ 
times very slender; third discoidal vein sometimes arising at or un¬ 
usually near the base of the stigma; wings sometimes clouded. Color 
usually pale yellow or pale brown. 
This is evidently an osculant group connecting the true Aphidini 
with the Lachnini , I have placed it at the end of the former tribe in 
preference to placing it at the commencement of the latter, as this 
appears to be the more natural position for the species. 
By this transfer the necessity for Passerini’s genus Pterocallis is en¬ 
tirely obviated. 
I think it quite probable that when the history and habits of this 
species become better known, and a natural grouping of species is un¬ 
dertaken, that it will be found necessary to bring together most of the 
species of Callipterus , Myzocallis , Pterocallis and Hyalopterus. Mr. 
Walsh’s genus Calaphis is evidently founded on an abnormal species, 
which I think beyond question belongs to the present group—either 
to this genus or Myzocallis. 
The absence of the fourth or stigmatic vein occurs occasionally in 
this group. By placing the wing under a strong microscope the line 
of the vein can be traced by an almost imperceptible row of minute 
hyaline dots. 
Callipterus betul.-e? Koch. The Birch Aphis. 
Aphis betidicolens? Fitch. 
Calaphis betidellaf Walsh. 
I am not positive that the species here mentioned are indentical 
but have concluded it is best to so consider them until further investi¬ 
gations shall determine this question. 
Koch’s species is more than usually large which agrees with the 
measurement given by Dr. Fitch, of his species. The winged female 
is greenish yellow; antennae and lobes of the throax black; head 
brown; legs dull yellow, except the shanks and tarsi of the front 
pair which are dusky; the veins oT the wings dark except the sub¬ 
costal, which is greenish yellow. The antennae are long reaching be¬ 
yond the tip of the abdomen; wings large; honey-tubes obsolete; body 
slightlv hairy; legs quite long. 
Dr. Fitch describes his species as follows: 
“Sulphur yellow; antennae deep black except the two basal joints, 
which are sulphur yellow; the following joints are white at the base. 
Nerves of the forewings black, the costal sulphur yellow, the base of 
the forked vein hyaline; stigma transparent yellow. Honey-tubes 
very short. Length, .18 inch,” [to tips of wings.] 
This is certainly not the Ajihis betulce of Linnaeus. 
Mr. Walsh’s species may be distinct but I doubt it very much; the 
absence, or apparent absence, of the fourth vein is not unknown in 
this group, and if of any value must as he argues, place it in a 
different genus. 
He describes his species as follows: 
