Somatochlora. 135 



hind border with a stronL;i\- inflated rim, ending; 

 abruptl}' on both ends ; sides a small elliptical lobe, bent 

 upwards ; stiL;'mata free ; w ing-cases reachini;" half of 

 sixth ses^ment ; abdomen once longer than bnjad, oblong, 

 roof-shaped, segments S and 9 sloping, the last truncate ; 

 segments of equal length ; the tenth \er}- short, entirely 

 inserted in the rounded ajjical notch of ninth ; lateral 

 spines on eighth and ninth flat, short, sharp ; a little 

 longer, the tip bent inwardl)-, on ninth ; dorsal hooks on 

 third to ninth spine-like, the last three strong, long, 

 bent at tijj ; anal a|)i)endages short, as long as the 

 last two segments, thick at base, p)"ramidal, not sharp 

 at tip ; dorsal median flat above, as long as inferiors ; 

 laterals a little shorter, strong, tip abruptly sharpened ; 

 longitudinal \entral sutures straight, ending inside of 

 apical tip of segment 9 ; space between them broader 

 than lateral spaces ; basal angle of segments 3 to 5 

 separated triangularly b\' an elevated ridge ; ventral 

 apical bc^rder of ninth segment \\ith a long fringe of 

 hairs. Legs widely separated, fore legs a little less, 

 long, strong ; femur a little incurved, of hind legs 

 reaching middle of se\enth segment ; tibia straight, of 

 the four hind legs fringed with long hairs ; tarsus 

 long, first joint of hind legs little shorter than second ; 

 claws strong, a little incurved, sharp ; genitals marked ; 

 ventral bag on sixth segment. Around the dorsal 

 hooks a round pale spot ; on each side an ill-defined 

 darker spot and two black dots on each side ; scars 

 oval, dark ; femora and tibiie with two blackish rings." 

 (L. Cabot, "The Immature State of the Odonata," 

 Part III. Memoirs of the Museum of Comparative 

 Zoology at Harvard College, U.S.xA., 1890.; 



