628 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.52. 



9. LIBELLULA SATURATA Uhler. 



Common. 



10. PLATHEMIS LYDIA (Drury). 



Several seen. 



11. ERYTHEMIS SIMPLICICOLLIS (Say). 



Common. This was flying about the edges of the pond in com- 

 pany with Pachydiplax. It is bolder in its flight than Pachydiplax. 



12. SYMPETRUM CORRUPTUM (Hagen). 



Common. 



13. SYMPETRUM ILLOTUM (Hagen). 



Several seen. 



14. PACHYDIPLAX LONGIPENNIS (Burmeieter). 



This was more common than I have seen it elsewhere in the West. 

 It is a shore-U^e species of ponds, seldom straying from the edge of 

 the water. Its habits are similar to those of Erythemis, with which 

 it is always associated. However, it usually rests Sympetrum-like on 

 the tips of snags and sedges at distances of one to 5 feet above the 

 water while Erythemis alights most often as close to the surface as 

 possible. The exuviae of Pachydiplax were common on logs and 

 the bases of trees where the n}miphs had crawled up from 1 to 3 

 feet above the surface of the water. 



15. PANTALA HYMENAEA (Say). 



Two individuals were caught flying with Tramea over a pasture 

 near the pond. Not common. 



16. TRAMEA LACERATA Hagen. 



Tramea was more abundant here than I have ever seen it else- 

 where. It was an interesting species because of its great dexterity on 

 the wing. In the early morning Tramea was found flying high and 

 wide, each on a short beat which was frequently changed. After 10 

 or 11 o'clock, when the heat of midday had increased their activity, 

 they were found over the surface of the pond ovipositing. I saw an 

 occasional female ovipositing unaccompanied by a male but usually 

 every female had a very attentive male companion. As Tramea 

 seldom alights, the male would catch the female on the wing. While 

 holding her the pair would fly about over the surface of the pond, 

 stopping occasionally to oviposit over the sm-face where this was 

 free from the scima of algae and duckweed. The pair woidd poise 

 about 6 inches above the sm-face of the water. The male would 

 release the female and remain poised while she would drop to the 

 surface, and with a short swing, tap the surface just once, when she 

 would rise to the male who would instantly grasp her thorax with 

 his claspers without first seizing her with his feet. This quick release 

 and the almost immediate reclasping of the female was one of the 

 most dexterous pei'formances I had ever observed in dragonflies. 



Exuviae were common on the stumps and logs lying about the 

 edges of the slough. 



