452 



MATERIALS FOR A FAUNA CANADENSIS. 



Under legs entire ; triangle without nervules ; eyes sepa- 

 rated , Gomphus. 



Under lip divided at its extremity ; eyes slightly touch - 



mg ' Cordulegaster 



Genera of Agrionina. 



Out of eleven given hy Rambur, only three seem likely to occur to 



the Canadian collector, which may be thus distinguished : 



more or less numerous ; pterostigma very Calopteryx. 

 small, or only seen in females 



Nervules of the 

 first Costal di- ■ 

 Vision 



two only- 



' pterostigma lozenge-shaped, small ; Agrion. 

 insects of small size ; areolse 

 quadrangular 



I pterostigma parallelogram-shaped; Lestes. 

 [ areolae often pentagonal 



SYNOPSIS OF THE SPECIES. 

 LiBELLULIDA. 



§1 LiBELLULINA. 



Gen. Nannophya. Rambur, 



N. BELLA, Uhler. — Black; front white, with a quadrangular 

 black spot ; dorsum of the thorax, each side with an interrupted yel* 

 low line on the male ; sides vnth two oblique stripes and a triangular 

 patch behind, interrupted, yellow ; abdomen black, with yellow bands 

 and spots — these parts in the female black, pruinose ; wings hyaline, 

 fulvous at the base in the male. Pterostigma small, black, terminated 

 with a white nervule at each end in the female : length 18 millimeters ; 

 alar expansion 33 mill : rather less in the female. 



Hob.: U. S. as far north as Maine. 



Gen. LiBELLULA, Linn, (as limited by Rambur.) 

 a. Perithemis, Hagen. 

 L. DoMiTiA, Drury. (Perithemis Domitia, Hagen.) 

 Posterior lobe of the prothorax large, broad, bilobed ; abdomen 

 much shorter than the wings, broad, depressed, narrower at the base ; 

 flavescent, villose; dorsum of the abdomen with an interrupted 

 brownish-black line on each side ; wings flavesecnt, or at least the 

 basal half, with two fuscous, transverse stripes, the internal one often 

 almost absent in the female ; pterostigma rufo-fuscous. In the North- 



