132 



Smith and Pritchard: Odonata 



-eg. 



4:48. Wings of Sympetrum vicinum 

 (Needham and Westfoll, 1955). 



— Tibia black 3 



2. Hamule broadly bifid on distal fifth (fig. 4:50^); dorsal 

 abdominal appendages convex on distoventral margin 

 (fig. 4:49<7) (British Columbia to California and east to 

 Montana and Colorado) pallipes Hagen 1874 



— Hamule with anterior branch ending well before end of 

 posterior branch (fig. 4:506); dorsal abdominal append- 

 ages concave on distoventral margin (fig. 4:496) 

 (British Columbia to California east to Maine and 

 Wyoming) costiferum Hagen 1861 



3. Radial planate subtending 1 cell row; dorsal abdominal 



appendages with a ventral tooth at distal end of denti- 

 culations (fig. 4:49c, d,f) 4 



— Radial planate subtending 2 cell rows; dorsal abdominal 

 appendages without a ventral tooth at distal end of 

 denticulations (fig. 4:49c) (British Columbia to Cali- 

 fornia, east to Montana) madidum (Hagen) 1861 



4. Hamule bifid for less than one-half its length (fig. 

 4:50rf,/,A) 5 



— Hamule bifid for more than one-half its length (fig. 

 4:50d) 7 



5. Hamule bifid for one-fourth its length or less, the 

 posterior branch with posterior edge bicuspidate .... 6 



— Hamule bifid for one-third its length, the posterior 

 branch semielliptical, concave, and shell-like (fig. 

 4:50A); face yellowish brown, (Canada, Nevada east to 

 New York) rubicundulum (Say) 1839 



6. Hamule bifid for one-fourth its length (fig. 4:50d); face 

 cherry red (Alaska to California east to Main) (=decisum 

 auct.) internum Montgomery 1943 



— Hamule bifid for one-fifth its length (fig. 4:50/); face 

 white (Alaska to California east to Maine (=decisum 

 Hagen) obtrusum Hagen 1874 



7. Hamule with anterior branch nearly as wide as posterior 

 branch; wings with only proximal spot flavescent 

 (Alaska to California east to New York) {=scoticum 

 Kennedy) danae Sulzer 1776 



— Hamule with anterior branch much narrower and much 

 shorter than posterior branch 8 



8. Dorsal abdominal appendages in mature specimens 

 pale (California, Nevada) 



occidentale calif ornicum Walker 1951 



— Dorsal abdominal appendages in mature specimens dark, 

 (California and Oregon to Colorado) 



atripes (Hagen) 1873 



Fig. 4=49. Lateral view of posterior end of male abdomen in the genus Sympetrum. a, ambiguum; 

 b, costiferum; c, danae; d, internum; e, madidum; i, obtrusum; g, pallipes; h, rubicundulum 

 (Needham and Westfall, 1955). 



