274 TERTIARY INSECTS OF NORTH AMERICA. 



1. Pterostigma recurvum. 



PI. 18, Fig. 18. 

 Pterostigma recurvum Buckt., Monogr. Brit. Aphides, IV, 178, PI. 133, Fig. 6 (1885). 



A single specimen with expanded wings lies entangled with a species 

 of Aphidinae (Tephraphis walshii). The basal joints of the antennse are 

 preserved, and show the characteristics mentioned under the genus. The 

 fore wings are nearly three times as long as broad, with scarcely any 

 fullness along the hind margin, being exceptionally symmetrical. The 

 thickened postcostal vein is almost straight, with the slightest possible curve 

 from the margin, and in the middle of the wing blends into the exceedingly 

 long, slender, and arcuate stigma, which curves around the tip of the wing 

 nearly to the middle line ; the costal margin is considerably arcuate at base 

 and distant from the postcostal vein. The oblique veins as far as preserved 

 are nearly straight and considerably divergent, but the second is only 

 preserved in its basal half or third ; it diverges from the postcostal 

 about forty degrees, the first as much as fifty degrees. The cubital vein is 

 very faint throughout, but arises about six times as far from the second 

 oblique as that from the first, and at only a short distance less than half-way 

 from the first oblique to the stigmatic vein ; it has a very longitudinal course 

 and forks narrowly, well before the base of the stigmatic vein and at from 

 one-fourth to one-third the distance from its origin to the extremity of its 

 lower branch. The stigmatic vein parts gently from the stigma and for most 

 of its course is straight, the stigmatic cell being narrow, broadest apically, 

 and nearly two-fifths as long as the wing. The openness of the first dis- 

 coidal cell apically can not be determined, but seems to have been three or 

 four times as broad here as at base. The abdomen seems to be oval, scarcely 

 broader than the thorax, and shows no signs of cauda or cornicles. 



Length of body, 4.25"°' ; of fore wing, 5.75™". 



No part of the wing is displaced by pressure, as suggested as possibly 

 the case by Buckton ; on the contrary it is exceptionally undisturbed ; but 

 as drawn on the plate the extreme base of the stigmatic vein is not given 

 (and is in reality very faint and only visible in certain lights), while the 

 apparent short vein close to its base is foreign to the wing. The obscure 

 cubital vein was overlooked when the drawing was made. 



Florissant One specimen, No. 8085. 



