THE CANADIAN ENTOMOLOGIST 417 



Other I have from De Grassi Point and Toronto only among Ciina- 

 dian localities and also from Blufifton, Ind., and Cedar Rapids, 

 Iowa. It may- be only a southern race of the same species, but it 

 appears to me to be distinct in both sexes from decision. The 

 latter is, in some respects, intermediate between the southern 

 form and obtrusiim, but certainly does not intergrade with the 

 latter. The question of the characteristics and status of these 

 forms of so-called rubicundtilum will be more fully discussed in a 

 future paper. 



Sympetrum scoticum (Donovan). 



The exuvia from Red Deer, Alta., already mentioned as hav- 

 ing been taken by Mr. Whitehouse with the imago is all I have 

 from North America to represent the nymph of S. scoticum, but I 

 found this species emerging from a pond in the Harz Mountains, 

 Germany, in 1906, and have several of the exuviae, though they 

 are, for the most part, in fragments. In most of these there is a 

 minute denticle to represent the dorsal hook of segment 8, but in 

 one of them and in the Red Deer specimen there is no indication 

 whatever of this structure. There is some variation also in the 

 length of the lateral spines, one of them having them scarcely- 

 longer than in the Prince Albert specimens of decisiim. It is very 

 probable that no external characters exist by which scoticum and 

 decisum can be separated with certaintv'. The number of lateral 

 setae is normally 11, sometimes 12, and the mental seta? var\' from 

 13 to 15, with 7 tQ 9 in the outer series. 



The colour pattern, as in most species of Sympetrum is very 

 indistinct and offers no characters of any value. 

 Sympetrum illotumi (Hagen). 



The nymph of this western species has not been fully de- 

 scribed, but a figure is given by Needham,* who has also noted* 

 the chief characters by which it may be distinguished from its 

 nearest relative. S. corruptum. 



Sympetrum corruptum^ (Hagen). 



The nymphal characters of this species have been described 

 by Needham'' from specimens taken in transformation b>" Prof. 

 T. D. A. Cockerell at Tempe, Ariz., and Las Vegas, N. M. 



4 Loc. cit., pi. 25, fig. 1. 



5 Bull. 68, N. Y. State Mus., p. 272, 1903. 



6 Loc. cit., p. 271, fig. 16. 



