NORTH AMKUIOAN ODONA'l'A. 235. 



% . Hind marsjin of prothorax entire, either side straight, convergent at a wide 

 angle to the middle, which is rounded. An apical spot on 8, gi'eater part of 9, 

 10 almost entirely, blue. Hind margin of 10 excised in the middle and denticulated. 

 Sup. app. excessively short, bifid, lower branch shorter. Inf. app. longer, with 

 three apical tubercles. 



9. Hind margin of prothorax tri-lobed, middle lobe smallest. An apical spot 

 on 9, apex of 10, blue. 



Abd. % 20-23, 9 20-22.5. H. w. % 13-15.5, 9 14-15. 



One % , Pa. (A. E. S.). One % , Berlin, N. J., July 17, by P. P. 

 Calvert (C). 



Maine to Pennsylvania, west to South Dakota ; Florida (Mrs. 

 Slosson, Cheney, Truman et al). 



14. Nehaleiiiiia. posita Hagen. 



Agrion p. Hagen, Syn. Neur. N. A., p. 77, 1861. N. p. Selys, Bull. Ac. Belg. (2) 

 xli, p. 1242, 1876. 



Metallic black, but frequently with a dark blue or dark greeu tinge. The 

 following light green, yellow or blue : frons, lips; a small, round, postocnlar spot 

 each side ; a short antehumeral stripe loith a spot above it. the two forming a ! mark ; 

 sides of thorax ; an interrupted transverse basal ring on 3-7. A black line on 

 second lateral suture. 



% . Hind margin of prothorax entire, rounded. Sometimes a blue dorsal spot 

 on 10, hind margin with an elevated bifid process, similar to that of males of 

 Ischnura. Sup. app. one-half as long as 10, directed downwards, with a small 

 supero-external tooth. Inf. app. slightly shorter. 



9. Hind margin of prothorax produced slightly in the middle. Antehumeral 

 stripe and spot above it often united. 10 sometimes blue. Thorax and al)donien 

 pruinose in old 9 9 • 



Abd. % 16..5-23. 9 18.5-22. H. w. % 10-14, 9 13.5-lR. 



Very common around Phila., May 1 — Oct. 2. 

 Quebec, Massachusetts, New Jersey, Pennsylvania, District of 

 Columbia, Georgia, Florida (Provancher, Skinner — A. E. S., C) 



7. Ainphiagrion Selys. 

 Selys, Bull. Ac. Belg. (2) xli, p. 284. 1876. 



15. Amphiasrioii Naucium Burmeister. 



Agrion s., Ag. discolor Burm. Handb. Ent. ii, p. 819, 1839. Amph. s. Selys /. c, 

 p. 285, 1876. 



Head dark brown or black, yellowish behind. Thoracic dorsum brnwn ( % ) 

 or reddish ( 9 ). sides yellow. Pterostigma brown, upper, outer angle very acute, 

 costal side longer than lower side. 



% . Abdomen bright red, frequently the extreme apical margin of 3-6. greater 

 apical part of 7, 8-10, black, sutures red : occasionally 7-10 red with black spots 

 each side. Sup. app. one-half as long as 10, simple, slender, directed downwards. 

 Inf. app. longer, curved slightly upwards. 



9. Abdomen red, black near apex of 3-6, 7-9 black, 10 reddish. 



Abd. % 17-22..5, 9 20-23. H. w. S 13.5-15.5, 9 14-17.5. 



TRANS. AM. ENT. SOC. XX. .SEPTEMBER. 1893. 



