294 NORTH AMERICAN TRYPETINA. 



whitish, only the bristles upon the posterior margin of the last 

 segment are black. Ovipositor black, hardly as long as the last 

 two segments taken together ; with distinct whitish pile upon its 

 anterior half. Feet yellow ; the femora for the most part black 

 or brown. The wings are comparatively a little longer and 

 narrower than in most of the related species. The rather dark 

 reticulation is loosely meshy and somewhat disconnected ; it 

 disappears almost entirely in the region of the posterior margin, 

 with the exception of a few little spots, which distinguishes this 

 species from the otherwise related ones ; the black stigma does 

 not include a hyaline dot ; the two ordinary dark spots are of 

 moderate size ; the first is connected with the stigma and reaches 

 from it directly backwards; the second usually contains, near the 

 anterior margin, only a single hyaline drop, which lies immedi- 

 ately beyond the tip of the second longitudinal vein ; this spot 

 reaches as far as the fourth longitudinal vein; the two rays which, 

 in the related species, run from this vein over the second poste- 

 rior cell to the posterior margin, are incomplete or wanting; the 

 posterior crossvein also has only a comparatively narrow dark 

 border, which sometimes exists on its posterior half only; upon 

 the posterior part of the crossvein, this border emits a short 

 branch, characteristic for this species, and reaching into the dis- 

 cal cell; this branch sometimes coalesces with a second similar 

 branch upon the posterior side of the fourth vein, so as to include 

 a hyaline drop ; otherwise the picture of the discal cell is limited 

 to a small crossband, lying beyond its middle, or there is some- 

 times before it, near the anterior margin of the cell, another dark 

 spot, which in some specimens becomes a second small cross- 

 band ; upon the posterior side of the fifth vein generally two 

 small, dark spots of variable size are observable, of which the 

 one nearer the root of the wing is often wanting. 



Hab. Yukon River (Kennicott). 



Observation 1. — I cannot distinguish this species from the T. 

 angustipennis occurring in Scandinavia ; the typical pair after 

 which I have described it in Germans Zeitschrift has, it is true, 

 the femora much less dark, but as the specimens seem to be 

 immature, I do not consider this a specific difference. The 

 figure given in Germans Zeitschrift has not well succeeded in 

 the engraving and gives only an approximate idea of the picture 

 of the wings. 



