THE CANADIAN ENTOMOLOGIST 209 



the subgenus (L. harberi Alex.) in its larger size and ditferent 

 coloration. 



Tribe Pediciini. 

 Genus Tricyphona Zetterstedt. 



Tricyphona degenerata, sp. n. 



Cell 1st Ah of the wings open by the atrophy of the outer 

 deflection of vein Mz\ wings small, somewhat degenerate, in the 

 male less than 5 mm. in length. 



Male. — Length about 4.8 mm.; wing 3.8 mm. 



Head lacking in the type. 



Pronotum light yellow. Mesonotum yellowish, the prccscutum 

 with a broad, dark brown, m.edian stripe and shorter lateral stripes 

 that continue back on to the anterior half of the scutal lobes; 

 scutellum and the remainder of the scutum yellow; postnotum 

 with a very sparse, grayish pruinosity. Halteres pale, the knobs 

 a little darkened. Legs with the coxae elongated, dull yellowish; 

 trochanters yellow, the margin at the junction with the femora 

 darkened; femora and tibiae brownish yellow, the tips of the latter 

 narrowly darkened; last two tarsal segments and the claws dark. 

 Wings long and slender, small, degenerate, although with a com- 

 plete venation; pale yellowish subhyaline, the. veins yellowish 

 brown; stigma indistinct. Venation (fig. 11) Rs angulated at its 

 origin; cross-vein r about twg-thirds the length of that portion 

 of R\ beyond it; petiole of cell Ri longer than the r-ni cross-vein; 

 forks of AI subacute; cell 1st Ah open by the atrophy of the outer 

 deflection of Ms. 



Abdomen dark brown, the hypopygium more reddish brown. 



Holotype, cf, Geneva Park, Grant, Colorado, altitude 9,500- 

 10,000 feet, July 22, 1916, (E. C. Jackson). 



The only other Tricyphona in the Nearctic fauna with the 

 cell 1st Ml open by the atrophy of the outer deflection of vein 

 Mz, is T. aperta Coq. (fig. 10), a full-winged fly that is much 

 larger than our present species. A comparison of figures 10 and 

 11 will show the chief difi^erences between the species. The con- 

 dition in the present species is one of degeneration, the wing 

 measuring but 3.8 mm.; the even more degenerate T. hannai 

 Alex. (Pribilof Islands) represents the culmination of this tendency 

 in the known species of the genus. 



