366 THE CANADIAN ENTOMOLOGIST 



CC. Lateral thoracic spots pale yellow, subovate, con- 

 spicuous; superior appendages of cf in profile arcuate, 

 with a very prominent ventrolateral tooth, which 

 affects the outline; vulvar lamina about as long as 



9th sternite fnrcipata Scudd . 



BB. Abdominal segments 5 to 7 without yellow spots, greatest 

 width of cf abdomen at distal end of seg. 6 or beyond. 

 D. Frons bounded below by a yellowish margin, 

 separating the metallic portion from post- 

 clypeus, the latter with yellowish lateral lobes; 

 hind wing of cf but little shorter than abdomen 

 (about 30:33),. the anal triangle more or less 



yellow kennedyi, n. sp . 



DD. Frons without a yellow inferior margin, the dark 

 coloration continuous with that of postclypeus, 

 which is wholly black; hind wing of cf decidedly 

 shorter than abdomen (about 26:38), anal 



triangle with a brown spot .franklini Selys. 



Somatochlora semicircularis Selys. 

 This species seems to be wholly western, and is apparently the 

 commonest species of the genus from the Rocky Mountains to the 

 Pacific Coast. References to semicircularis from eastern localities 

 (Williamson, Ent. News, April, 1906, p. 136, pi. V, figs. 2, 3, 4) 

 apply to 6'. kennedyi. 



S. semicircularis is easily recognized by the form of the male 

 abdominal appendages and the vulvar lamina of the female, together 

 with the black lateral lobes of the clypeus. The lateral thoracic spots 

 are conspicuous in young individuals but of a ^deeper yellow than 

 in forcipata, and the metepimeral spot is usually much smaller. 

 Lateral abdominal spots are generally present but are variable 

 and sometimes absent. The extent of these variations are well 

 shown by Kennedy (Proc. U. S. Nat. Mus., 46, 1913, pp. 111-126, 

 figs. 1-57). It is the stoutest of the five species of the group. 



Material studied.— 68 cT's, 21 9's; Banff, Alta., June 29-31, 

 1913, 5 cf's 2 9's, (Walker and Kurata) ; Nordegg, Alta., 6,500 

 ft., July 16, 1917, 1 d", (F. C. Whitehouse) ; Mt. Benson, Van- 

 couver Is., B.C., July 21, 1909, 4 cf 's 1 9 ; id., July 23, 1909, 1 9 , 

 (A. G. Huntsman); Departure Bay, Vane. Is., July 13, 1908, 



