34 DRAGONFLIES OF OHIO. 



(3). Superiors more than half of 10, two widely divaricate 

 branches, the upper thicker, slightly longer ; inferiors a little 

 shorter than the inferior branch of superiors Bscheri. 



(4). Superiors longer than 10, end obliquely truncate with a tooth 

 ( lower branch) at outer third; inferiors slender signatum. 



(5). Superiors shorter than 10, securiform; inferiors as long as 

 lower angle of superiors, ver^' slender poUutum. 



Enallagmn ebrium, Hagen. 



Length : of abdomen c? 25, ? 23 ; of hind wing of 

 d' 17, ? 18. 



The male is bright blue marked with black. The 

 occiput, vertex, antennje, and postclypeus are black; 

 occipital spots large ovate and connected , the pro- 

 thorax has a line on sides, posterior border and an 

 ovate spot each side blue; thorax with a broad mid- 

 dorsal, humeral and greater part of legs black; black 

 on abdomen as follows : square basal spot on 1, apical 

 spot and ring on 2—6 (these spots are successively 

 larger, pointed anteriorly and occupy from one fourth 

 to one half of the dorsum of the joints ). the whole of 

 7 and 10, and the appendages. The female differs in 

 the ground color which is yellowish green, the black 

 markings of head and thorax are similar to those of 

 the male, the legs are lighter, the pterostigma is light 

 yellow, the entire thoracic dorsum is black except 

 interrupted basal rings on 2—7. 



The superior male appendages from above are 

 divaricate, curved toward the middle-line and have a 

 pointed booklet just before the end within ; in profile 

 bifid, the upper branch straight, stout, obtuse; the 

 lower narrower curved down then up making the sinus 

 broad and rounded. The inferiors are as long as the 

 superiors, curved slightly upward and inward, they 

 .are blue at base then black. 



The female appendages are stout, about the length 

 of 10. pale and the valves including the process yellow\ 

 The black sternal line includes the ventral spine of 8. 



