120 CONTEIBTJTIONS TO CANADIAN PALiEONTOLOGY 



posterior branch strikes the lower margin about in the centre. The 

 first anal vein is strongly divergent. The mediocubitall cross-vein is 

 only one and one-half times as far removed from the radiomedial 

 cross-vein as this is from the bifurcation of the media. The wing 

 appears uniformly transparent, and only on the anterior border some- 

 what opaque. 



Penthetria dilataia, sp. nov. Pig. 28. 



Locality: Horsefly mine— (July 20, 1906. L.M.L.). 



A remarkably broad wing 10™™ long, with slightly curved anterior 

 margin and strongly arcuate posterior border. The breadth to the 

 length is as 1:1-9. The radius, which bends slightly forward 'at the 

 end, extends beyond seven-tenths the length of the wing. The sector 

 arises just above the end of the first third of the wing's length, and 

 is strongly sigmoid in- curvature. It dichotomizes in half its length 

 into widely divergent branches: the anterior of which is gently 

 curved, land fuses in the margin midway between the radius and the 



' Fig. 28. — Penthetria dilatata, Haudlirsch. 



posterior branch of the sector. The radiomedial crosB-vein lies some- 

 what farther from the origin than from the furcation of the sector 

 and just above the middle of the wing. Somewhat below the centre 

 of the wing the media divides into two strongly divergent branches. 

 The cubitus with its posterior branch falls off abruptly but in ia 

 gentle curve toward the posterior border, which it strikes some 

 distance 'above the centre. Behind the cubituls runs a parallel fold, 

 and farther on a simple slightly divergent anal vein. The medio- 

 cubital vein lies one and one-half times as far above the radiomedial 

 cross-vein as is the latter above the forking of the media. The costal 

 region is densely opaque. 



