THE CANADIAN ENTOMOLOGIST 413 



7. Lateral setae 11, dorsal hooks vestigial or aljsent from segs. 



4 and 8 scoticum 



Lateral setae 9 or 10, dorsal hooks somewhat larger, generally 

 present, though small, on segs. 4 and 8 obtriisum 



8. Lateral setae 9, mental setae about 13, 7 in the stronger, outer 



series illotu m 



9. Lateral setae 13-14, mental setae about 17, 9 in the outer 



series , corruptnm 



Sympetrum semicinctum fSay). 



I have seen but one specimen of this species, received from 

 Prof. Needham. Its characters seem quite distinctive. The 

 comparatively blunt, inferior appendages distinguish it from all 

 other species I have seen. It was described and figured by Need- 

 ham in Bull. 47, N. Y. State Mus., p. 523, pi. 25, f. 2. 



Sympetrum vicinum (Hagen). 



The prominent eyes, large, dorsal hooks and long, slender 

 lateral spines render this an easily recognized species. I have 

 examined a considerable number of specimens from various locali- 

 ties and have reared it several times, both in Ontario and on 

 Vancouver Island. It has been described by Needham (1. c; 

 p. 522). 



Sympetrum costiferum (Hagen). 

 This species was described by Needham from a single, some- 

 what collapsed exuvia. The dorsal hooks on segments 6-8 are 

 described as being about as long as their respective segments. 

 They are usually somewhat shorter. 



1 have not actually reared this species, but I found a freshly- 

 emerged male with its exuvia in a shallow reed-bed at the edge 

 of a lake on Gabriola Island, B.C., Aug. 12, 1913. I also found a 

 number of exuviae on small reeds in a shallow, sand-bottomed 

 lagoon on the Giant's Tomb Island, Georgian Bay, Ont., July 29. 

 1908. Adults of S. costiferum were flying here in abundance. I 

 have also a few nymphs dredged from several localities in Georgian 

 Bay. 



The nymph is easily distinguished from that of S. ohtriisum 

 by the larger size and longer lateral spines and dorsal hooks, the 



