178 NEUROPTERA OF NORTH AMERICA. 



8. D. berenice! 



Libellula berenice Drury, Ins. 1, 114; tab. xlviii, fig. 3. Oliv. Enc. Meth.; 

 Say, Jour. Acad. Philad. VIII, 25, 13 ; Rambur, Neuropt. 88, 80. 

 Libellula histrio Burm.! Handb. II, 849, 7. . 



Black ; mouth black, the labium yellow each side ; front black 

 beneath, with a yellow spot each side, above and the vertex cha- 

 lybeous; eyes black posteriorly, spotted with yellow ; thorax black, 

 subpruinose ; the sides of the same color, or (teneral) with some 

 yellow spots towards the legs ; feet black ; abdomen slender, tri- 

 quetral, the base hardly inflated, altogether black, subpruinose 

 (adult male), or with segments 3 7 having a yellow spot each 

 side (male and female, less adult) ; or black, and segments 3 7 

 with a large, phalerated, fulvous spot, divided by a medial black 

 line; the last segment partly fulvous (teneral female) ; appendages 

 black; the vulvar lamina long, erect, triangular, excavated; wings 

 hyaline, base of the posterior ones, in the female, subrufous; ptero- 

 stigma long, yellow; membranule black. 



Var. 9 (L. histrio Burm.). Labium yellow, the middle nar- 

 rowly black ; labrum yellow, margined with black ; front yellow, 

 with a transverse black stripe, and a small T-shaped chalybeous 

 spot above ; vertex chalybeous, with a bright yellow spot above ; 

 prothorax black, spotted with yellow ; thorax bright yellow, the 

 middle sulcus and a double stripe, which is joined together at each 

 end, black; sides yellow, with five partly interrupted, oblique, black 

 streaks; the more adult female has the black markings broader and 

 more confluent ; feet black, extreme base of the femora yellow ; 

 abdomen black, segments 1 7 with a large, dorsal, phalerated 

 spot, incisures black ; the tenth segment and appendages fulvous ; 

 wings hyaline, the extreme base flavescent, all -the wings with a 

 large medial, fuscescent cloud ; pterostigma yellow ; membranule 

 black ; nine antecubitals ; 7 9 postcubitals ; three discoidal are- 

 olets. 



Length 32 34 millim. Alar expanse 50 rnillim. Pterostigma 

 3 millim. 



Hob. Bergen Hill, New Jersey (Guex) ; New York; Maryland 

 (Uhler); Virginia. A common species. I possess a male and 

 female of the variety, taken in copula. 



