90 DRAGONFLIES OF OHIO. 



Male; frons, labrum and labium yellow, other parts 

 of front olive. In some specimens the whole front is 

 olive. Thorax with a covering of long pubescence, two 

 angular, yellow spots in front of the inferior half of the 

 second lateral suture, these spots and both sutures mar- 

 gined with metallic blue. Basal two thirds of front 

 femora yellowish or light brown, remainder of legs dark 

 brown to nearly black. Fore wings hyaline; hind wings 

 with a basal streak between subcostal and median veins 

 extending to first antecubital, the space at extreme base 

 between submedian and post-costal veins and a triangu- 

 lar patch occupying the lower part of the anal triangle 

 and part of at least three neighboring cells, fuscous ; re- 

 mainder hyaline. 



The dark markings of the wings are variable, but 

 in none of our specimens do they extend much beyond 

 what I have indicated, they may be very much reduced 

 however. Abdomen fuscous with yellow markings on 

 the sides of segments 2-9. Superior appendages as 

 long as 9 + 10, the apical two thirds (nearly) thickened. 

 From above separated at base, gradually approaching 

 one another for one half their length, then diverging to 

 apex. Inferior appendage reaching the middle of the 

 thickened portion of the superiors, oblong conical, ex- 

 panded laterally at extreme apex. 



Female vulvar lamina composed of two horn-like 

 lobes whose apices reach beyond the extent of the ninth 

 segment. 



The species is a common one in all parts of Ohio. 



Tetragoneuria semiaqua, Burm. 



Length : of abdomen d 26-27, 9 28 ; hind wing d 

 25-28, 9 29. 



This species is very close to cynosura. Color alone 

 is used to characterize it. The fuscous at the base of 

 the hind wing is much extended, and occupies nearly all 

 the space between the base of this wing and a line 



