THE CANADIAN ENTOMOLOGIST 225 



Walker. The flies were generally observ^ed in small swarms among a dense 

 growth of Equisetum hiemale that covered the embankment. 



Ormosia notmani, sp. n. 



General coloration dark brown, the praescutum without stripes; wings 

 grayish subhyaline, the stigma slightly darker brown; cell Isi M2 open by the 

 atrophy of the outer deflection of Mi; basal deflection of Cu\ very oblique in 

 position, inserted beyond the fork of M; 2nd Ajial vein bent toward the 1st 

 Anal on its outer end only; male hypopygium complicated; outer pleural ap- 

 pendage a black, three-spined structure; inner pleural appendage slender, deeply 

 bifid; gonapophyses slender, the distal end slightly widened, each apophysis 

 with a long, powerful spine at the base. 



Male. — Length about 3.8 mm.; 4.4 mm. 



Rostrum and palpi dark brown. Antennae slightly elongated, dark brown, 

 the scapal segments a little paler; flagellar segments long-oval, provided with 

 a dense, erect, white pubescence. Head brownish gray, provided with long. 

 \ellow bristles. 



Pronotum brown, the scutellum obscure yellow. Mesonotum dark brown? 

 sparsely dusted with a grayish yellow pollen; pseudosutural foveae conspicious» 

 oval, black. Pleura brown, sparsely dusted with gray. Halteres light yellow- 

 Legs with the coxse and trochanters light yellow; femora light brown, brighter 

 basally; remainder of the legs darker brown. Wings grayish subhyaline; stigma 

 slightly darker, brown; wing-base a little brighter; veins dark brown. Venation: r 

 less than its own length beyond the fork of i?2+3 on R^; cell 1st Mo open by the 

 atrophy of the outer deflection of Mz; basal deflection of Cui a short distance 

 beyond the fork of M, very oblique in position, the branches of Cu forming an 

 angle of about 100°; 2nd Anal vein with the extreme outer end bent toward the 

 1st Anal. 



Abdomen dark brown, the hypopygium a little brighter. Male hypopygium 

 somewhat as in 0. hilineata Dietz and 0. suhcornuia Alexander but very distinct 

 in the details of structure. Outer pleural appendage a short, squat, chitinized 

 structure that terminates in three acute blackened points, the two outer ones 

 short and sub-equal, the inner spine much longer, acute; inner pleural ap- 

 pendage long and slender, almost straight, profoundly bifid, the two arms 

 lying generally parallel, the one arm appearing as a long, blackened spine with 

 the proximal face microscopically serrulate, the other, more dorsal, arm slightly 

 paler, sparsely setigerous. Gonapophyses shaped as slender blades, the outer 

 ends a little flattened and expanded, at the base of each with a powerful, semi- 

 erect spine that is about one-third the length of the apophysis. Ninth sternite 

 with a conspicuous fleshy spatulate lobe as in the meigenii group of species. 



Habitat.— New York. 



Holotype.— (f, Keene \ alley, Essex Co., May 26, 1920, (Notman). 



Type in the collection of the author. 



This remarkably distinct species is dedicated to the collector, Mr. Howard 

 Notman. whose conscientious and capable efforts have added numerous species, 

 in many orders, to the list of New York insects. 



