TWO FOSSIL INSECTS FROM FLORISSANT, COLORADO, 

 WITH A DISCUSSION OF THE VENATION OF THE 

 AESHNINE DRAGON-FLIES. 



By T. D. A. COCKERELL, 



0/ the University of Colorado, Boulder. 



The Florissant shales continue to yield important new materials 

 for the study of Tertiary insect life. The specimens now discussed 

 are of special interest because of their relation to certain modern 

 forms, and in one case the investigation has been extended to include 

 the venational characters of the aUied modern genera. 



Order ODONATA. 



Fanuly AESHNID^. 



OPLON^SCHNA LAPIDARIA Cockerell and Counts, new species.' 



Hind wing of male; length about 42 mm.; hyaUne, venation 

 piceous; stigma dark piceous; stigma 5 mm. long, bounding 3| long 

 cells below; triangle of five cells, two basal, the formula 2, 1, 1, 1; 

 branches of media leaving arculus considerably below middle; M3 

 and M4 at margin of wing separated by two cells, M4 and the supple- 

 ment also separated by two (one only in 0. armata); M4 without 

 any evident deflection or bulging about six cells from margin (such 

 a bulging very distinct in 0. armata)', Rs unbranched, separated 

 from the supplement below it by about five rows of cells at widest 

 part (three or four in 0. armata). 



Compared with the hving 0. armata, the stigma is much longer, 

 and in the type-spe6imen has a cross vein (Mr. E. B. WiUiamson 

 thinks this is a freak, but that such freaks are probably confined to 

 species with a long stigma. Needham's figure of Tachopteryx, which 

 has an excessively long stigma, appears to show a cross vein); the 

 cell beyond the stigma is not nearly twice as long as the next follow- 

 ing one; the origin of the branches of the media from the arculus is 



1 This species was first studied and drawn by Miss Hilda Counts, whose work has been incorporated in 

 this paper. 



Proceedings U. S. National Museum, Vou. 45— No. 2000. 

 80459°— Pi'oc.N.M.vol.45— 13 37 577 



