123 



Smith and Pritchard: Odonato 



5. 



7. 



1. 



4. 



Superior appendage with distal tooth short, not exceed- 

 ing tip of appendage 6 



Superior appendage with distal tooth slender, reaching 



well beyond tip of appendage (fig. 4:32c) 7 



Rear of head partly fuscous or yellowish (Canada and 



western U.S.) umbrosa* Walker 1908 



Rear of head black (California, Nevada, to Baja Cali- 

 fornia) walkeri Kennedy 1917 



Abdomen with venter entirely black (eastern U.S., 



British Columbia to Baja California) 



constricta Say 1839 



Abdomen with venter largely pale (Alaska to California 

 and Colorado) palmata Hagen 1856 



Females 



Abdomen with a tubercle on the venter of segment 1 

 2 



Abdomen without a tubercle, on the venter of segment 1 



7. 



Face with a brown or black line on frontoclypeal suture 



calif ornica Calvert 



Face without a black line on frontoclypeal suture 



multicolor Hagen 



Styli as long as the dorsum of abdominal segment 10; 



appendages broadest before middle (fig. 4:30) 



constricta Say 



Styli much shorter than dorsum of abdominal segment 



10; appendages broadest beyond middle 4 



Genital stylus with a tiny pencil of hairs; genital 



valves with apices not elevated 5 



Genital stylus without a tiny pencil of hairs; genital 



valves with apices elevated 7 



Mesothorax with dorsal pale stripes absent or repre- 

 sented by a small spot; face with a black line on 



frontoclypeal suture interrupta Walker 



Mesothorax with dorsal pale stripes present; face 



without a black line on frontoclypeal suture 6 



Mesothorax with first lateral pale stripe having anterior 



margin sinuate verticalis Hagen 



Mesothorax with first lateral pale stripe having anterior 



margin straight walkeri Kennedy 



Rear of head pale; face without a black line on fronto- 

 clypeal suture umbrosa Walker 



Rear of head black; face with a black line on fronto- 

 clypeal suture palmata Hagen 



Naiads 



1. Blade of lateral lobe of labium wider than in figure 

 4:31a or b 2 



- Blade of lateral lobe of labium shaped as in figure 

 4:31a; femora concolorous constricta Say 



2. Blade about like figure 4:31c; mentum of labium about 

 V/i times as long as greatest width 3 



|l — Blade wider than figure 4:31c; mentum of labium about 



1.3-1.6 times as long as greatest width 5 



J 3. Blade with minute triangular tooth on innermost angle; 



femora concolorous verticalis Hagen 



I — Blade merely sharply angulate at innermost angle; 



femora striped 4 



5 4. Lateral spines of abdominal segment 8 shorter than 9, 



6 rudimentary multicolor Hagen 



— Lateral spines of abdominal segment 8 longer than 9, 



6 well developed calif ornica Calvert 



5. Blade of lateral lobe of labium shaped as shown in 

 figure 4:31a* 6 



| — Blade of lateral lobe of labium shaped as shown in 

 figure 4:31e 7 



6. Blade of lateral lobe of labium with minute tooth on 

 innermost angle interrupta Walker 



A. umbrosa umbrosa Walker 1908, a Canadian subspecies. 

 A. umbrosa occidentalis Walker 1912, occurring from Alaska to 

 Utah, Nevada and California. 



3 — 



Fig. 4:33. Wings of Gynacantha nervosa 

 (Needham ond Wostfoll, 1955). 

 Blade of lateral lobe of labium sharply angulate at 



innermost angle walkeri Kennedy 



Mentum about 1.3 times as long as greatest width; 

 ovipositor of female about one and one-third times as 



long as segment 9 palmata Hagen 



Mentum about 1.6 times as long as greatest width; 

 ovipositor of female about one and one-tenth times as 

 long as segment 9 umbrosa Walker 



Genus Gynacantha Rambur, 1842 



Gynacantha represents a group of aeshnine genera 

 of dragonflies that are found in the tropics. The only 

 species found in the United States, G. nervosa 

 Rambur, 1842 (fig. 4:33), ranges widely over Central 

 and South America, and it has been found in southern 

 Florida and southern California. This is a large, 

 dusky brown species with green markings, particularly 

 at the base of the abdomen. Adults fly only for a 

 short period in the evening and early morning. Females 

 lay eggs in soil near water. 



The type of the genus Gynacantha was first desig- 

 nated by Kirby 1890, as G. trifida. Previously, how- 

 ever, Selys, 1857, made G. trifida the type of his 

 genus Triacanthagyna, because the female is gener- 

 ically recognizable by the triacanthagyne charac- 

 teristics. 



It is true that Gynacantha, with seven originally 

 included species, was without a type species until 

 Kirby's designation, which should be accepted under_ 



Fig. 4:34. Wings of Tr/acanthogyno trifida 

 (Needham and Westfoll, 1955). 



