382 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 37. 



A very short antehumeral stripe, 1.5-2 mm. long on the mesepi- 

 sternum. Latero-ventral metathoracic carina yellow. Yellow ring 

 on abdominal segment 2 not interrupted dorsally or laterally. Costa 

 dark colored. 



Male. — Postclypeus and labrum similar to illinoiensis; dorsal spots 

 on frons rounded, in size from scarcely perceptible to nearly 1 mm. in 

 diameter, and always larger than the lateral spots. 



Abdominal spots on 3-6 larger than in illinoiensis, growing suc- 

 cessively smaller posteriorly, the spot on 3 extended ventrally on 

 either side to meet a longitudinal stripe on the ventral edge of the 

 segment (in illinoiensis the dorsal spot is widely separated from the 

 ventral longitudinal stripe) ; on 3-5 the spots on each segment are sepa- 

 rated dorsally by the faintest line of black or the black line may be 

 wanting; in two cases the spots on 6 meet dorsally; the greatest va- 

 riation in size of spots is on 6, where the spots may be widely sepa- 

 rated and about 0.5 mm. long, or joined dorsally and 1 .5 mm. in length ; 

 spots never wanting on 3-6 ; 7 similar to illinoiensis; spot on 8 ^ to f 

 as long as on 7, divided dorsally in only one case, and then by the 

 merest line of black. 



One male from Wister, Oklahoma, is very dark and may not belong 

 here; the tibial keels are like australensis, but the coloration is more 

 like illinoiensis. However, the head is like a very dark illinoiensis, 

 while the abdomen has an unusual amount of yellow for illinoiensis; 

 the antehumeral stripe seems to be wanting and the yellow ring on 2 

 is narrowly interrupted dorsally and laterally; well developed spots 

 are present on 6 and 8. In australensis 7 may be yellow or not on 

 the ventral basal edge of the segment; in any case the yellow is less 

 distinct than on 8 and 9. 



Wings hyaline, without trace of color anywhere even in teneral 

 specimens; stigma black. 



Abdominal appendages indistinguishable from illinoiensis. 



Female. — Head similar to illinoiensis, but dorsal spots on frons 

 apparently not larger than in male. Abdomen similar to male, but 

 spots on 3-6 more nearly uniform in size, sliglitly smaller on 6, 1.5-2 

 mm. long on 3-5 ; dorsal spot present on 7 ; inferior lateral basal spots 

 present on 7-9. 



Wings hyaline, short brown basal streaks in the costal or costal 

 and subcostal areas; apex of wings slightly fumose in two specimens; 

 stigma yellowish brown to black. The wings of three females show 

 the following: Triangle of front wing, free 1, crossed 5; subtriangle of 

 front wing, free 1, crossed 5; triangle of hind wing, crossed 6. 



I can not be sure of the shape of the vulvar lamina; it seems to be a 

 very short, scarcely emarginate plate; appendages similar to illinoi- 

 ensis. 



Types. — Male and female, author's collection taken at Wister, Okla- 

 homa, Poteau River, Frank Collins, August 3, 1907, 



