DIPTERA— MYCBTOPniLID.!;. 587 



othei' of the numerous species mentioned in his monograph of the group. 

 The costal and first and second longitudinal veins, together with the cross- 

 veins uniting the two hxtter, are much heavier and darker than the other 

 veins of the wing ; the veins near tlie center of the wing and from there 

 toward the base are more dehcate and fainter than elsewhere; but this 

 perhaps is due to their indifferent preservation ; the costal vein, wliich 

 scarcely fails of reaching the tip of the wing, is covered with fine and short 

 spinous hairs. The first longitudinal vein strikes the middle of the costal 

 marg-in, and the cross-vein below unites it at the middle with the second 

 longitudinal vein ; the auxiliary vein is very obscure though broad and 

 scarcely extends more than half-way to the cross-vein, in close juxtaposi- 

 tion to the first longitudinal vein ; the transverse shoulder vein is equally 

 faint, oblique, uniting the middle of the auxiliary vein with the costal mar- 

 gin. The second longitudinal vein is strongly bowed and extends nearly 

 to the tip of the costal vein. The basal undivided part of the third longi- 

 tudinal vein is straight, originates from the second barely beyond the tip of 

 the auxiliary vein, and forks somewhat abruptly at the middle of its course 

 and just beyond the extremity of the first longitudinal vein; shortly 

 beyond their origin the forks are very nearly straight and quite parallel to 

 the tip, the upper fork striking exactly the tip of the wing ; the tips of the 

 two forks and of the second longitudinal vein are equidistant, and the costal 

 vein terminates midway between the extremity of the second and of the 

 upper fork of the third longitudinal vein ; the tip of the fourth is slightly 

 farther from that of the lower fork of the third longitudinal vein than the 

 separation of the two forks. The fourth and fifth longitudinal veins are 

 straight and subparallel at base, beginning to diverge where they bend 

 downward, just beyond the middle, the tip of the fourth lying about mid- 

 way between that of the fifth and the lower fork of the third longitudinal 

 vein. The sixth longitudinal vein is rudimentary and very indistinct, 

 extending less than a quarter-way toward the margin. 



Length of wing, 2.75"""; breadth, 1.25""". 



Quesnel, British Columbia. One specimen, No. 44 (Dr. G. M. Daw- 

 son, Geological Survey of Canada). 



