12 DRAGONFLIES OF OHIO. 



ish narrow interrupted rings on 3—7, and a more or less 

 distinct mid-dorsal, light line on 2-7. 



The superior abdominal appendages are'forcipated, 

 light below and darker above especially towards the 

 apex; the outer surface is denticulate in the middle; 

 there are two smooth horizontally flattened protuber- 

 ances on the inner side, the proximal one is the larger, 

 the rounded apexes of these processes'are directed away 

 from each other. 



The inferior appendages arc broad at base, then 

 narrow and cylindrical, the truncated apex reaches to 

 the larger tubercle of superiors and bears a stout den- 

 ticle on its inner angle. 



The females have the head, thorax and abdomen 

 metallic green, the last becoming obscure with age. 

 There are markings of other colors as follows; antennae 

 ( except basal joints ), a dot in middle of labrum, mid- 

 dorsal carina, the tarsi, the outer side of legs and 

 sternum black ; the under side of head and Ihorax, 

 sides of abdomen (except a dark apical spot), basal in- 

 terrupted ring on 1—7, a mid-dorsal line on 1—10; basal 

 joints of antenna, labrum, edges of the prothorax, 

 humeral stripe and stripes on the side as in the male, 

 white. The wings are hyaline, costa black, basal third 

 and front margin pale yellowish brown. Pterostigma 

 white, surrounded by black veins. The abdominal ap- 

 pendages and valves are 3^ellowish, the latter tipped 

 with black. 



This brilliant gem is peculiarly restricted in its 

 scene of flight. It is rarely observed more than a few 

 feet away from its accustomed habitat, the water's 

 edge. Another notable habit is that of congregating, 

 sometimes in companies of hundreds. These assem- 

 blies commence in the afternoon and do not disperse 

 until the warmth of the following day awakens them to 

 activity. Both sexes take part in these assemblies and 

 they rest so compactly that a single sweep of the net 



