1875.] 149 [Osten Sacken. 



In the female the lunate spots are also cut in two, as they are in the 

 typical specimens. 



8. S. lapponicus. 



S. lapponicus Zetterstedt, Dipt. Scand., n, p. 701, 3. 



f Scceva affinis Say, Journ. Acad. Phil., in, 93, 9. 



I compared ten specimens from the north-western regions of the 

 British Possessions (R. Kennicott), from the White Mountains, N. H. 

 (E. P. Austin, H. K. Morrison, and myself), and from British Colum- 

 bia, which agree with Mr. Zetterstedt' s description. A North 

 American specimen of the same kind, sent to Mr. Loew, was ident- 

 ified by him as S. lapponicus. 



A number of other specimens, nearly from the same localities, 

 White Mts. (H. K. Morrison), British Possessions (Scudder), Que- 

 beck (Belanger) and Yukon River (Kennicott), have the third 

 longitudinal vein less strongly sinuate, and show some other minor 

 differences. The European S. arcuatus Fallen differs from S. lap- 

 ponicus in hardly anything but this very character, and is neverthe- 

 less considered a different species. 



Scceva affinis Say (from Arkansas) does not seem to differ from 

 S. lapponicus in any important character, and specimens from Dela- 

 ware, Illinois, etc., which I have seen, may be identified with it. 

 Thus the uncertainty whether I have one or several species before 

 me, prevents me from giving a description. 



Should it be proved that Scceva affinis Say, is a synonym of S. 

 lapponicus, then Say's name, as by far the oldest, would have the 

 priority. 



Syrplius Agnon and S. arcucinclus Walker are either S. lapponi- 

 cus, or some allied species; the descriptions are altogether un- 

 meaning. 



9. S. diversipes. 



S. diversipes Macquart, Dipt. Exot. 4 e Stippl., p. 155, 54 (New- 

 foundland). 



? S. cinctellus Zetterstedt, Dipt. Scand., u, p. 742, 45. 



Male and female. Abdomen narrow, with nearly parallel sides; 

 first segment (cf) greenish' black, with more or less yellow anteriorly, 

 or on the sides; in the ? the yellow prevails, leaving only a metallic 

 green spot on each side, which often is subobsolete; the following 

 four segments have each a yellow crossband on their anterior half; 

 the first crossband is broadly interru ted; in the male the interrup- 

 tion takes the shape of an inverted black triangle, expanding ante- 



