264 TEETIAEY INSECTS OF NORTH AMERICA. 



4. Aphidopsis margarum. 



PI. 18, Fig. 8. 



This small and slender species is very dark, almost black as preserved, 

 and pretty uniform. The antennae so far as preserved are excessively 

 slender and rather shorter than the wings. Wings about three times as 

 long as broad, the postcostal vein heavy, uniform, and straight, merging 

 into the stigma, which is twice as broad, bat very long and slenderly fusi- 

 form. The first oblique vein is perfectly straight and parts from the post- 

 costal at au angle of fully seventy-five degrees; the second oblique vein, 

 also perfectly straight and rather distant from the first, parts from the post- 

 costal at an angle of forty-five degrees, so that the first discoidal cell is 

 about three times as broad on the hind margin as at the base. Cubital 

 vein very stiff" and angular, it and both its branches being rigidly straight ; 

 at each furcation it is bent, forking first at rather more than a third wa}" to 

 the hind margin and again about half-way to the apex of the wing, not 

 ap])roaching closely to the stig-matic vein ; the vein originates at more than 

 half-way from the first oblique vein to the stigmatic. The stigmatic vein 

 arises far back, about midway between the forks of the cubital, and i§ very 

 longitudinal, so that the stigmatic cell is narrow, and exceeds a third the 

 length of the wing. Legs very slender. 



Length of body, •2.5-3"'"; antenripe, 3.4'"'°; wings, 3.75-4"""; middle 

 legs, 2.6'"'". 



Florissant. Three specimens, Nos. 5380, 12190, 12683. 



5. Aphidgpsls dalli. 



The head and thorax darker than the tolerably uniform abdomen. 

 Antennae at least half as long again as the body. Wings apparently about 

 three times as long as broad, the postcostal slender, the stigma pretty large 

 and very long. First oblique vein straight, or nearly straight, parting from 

 the postcostal at an angle of about fifty-five degrees ; second oblique rather 

 distant from it, parting at an angle of forty-five degrees, and likewise nearly 

 straight, so that the first discoidal cell between them is little more than twice 

 as broad on the hind maro'in as at the base. Cubital vein arisina; more than 

 twice as far from the second oblique vein as that from the first, and about 

 midway between the latter and the stigmatic vein, first forking when hardly 



