94 PROCEEDINGS OF THE ACADEMY OF [Part 1 



Manaos, Brazil (W. M. Mann). 



Yurimaguas, Peru, March 29-April 20, 1920 (H. S. Parish). 



Genus MEGISTOCERA Wiedemann. 

 1828. Megistocera Wiedemann, Aussereur. zweifl. Ins., Bel. 1, p. 55. 



Megistocera longipennis (Macquart) 



1838. Tipiila longipennis Macquart, Dipt, exot., Tome 1, pt. 1 p. 57. 



Obidos, Brazil, September 23, 1919 (H. S. Parish). 

 Yurimaguas, Peru, April 8, 1920 (H. S. Parish). 



Genus OZODICERA Macquart. 

 1834. OzocUcera Macquart, Suites a Buffon, Tome 1, Hist. Nat. Ins., 

 Dipt., p. 92. 



Ozodicera (Dihexaclonus) triguttata sp. n. 



Flagellar segments two to seven pale yellowish brown, each with 

 two short, pale pectinations; mesonotum light brown, the prae- 

 scutum with four slightly darker stripes; femora broadly tipped 

 with brownish black; wings reddish brown with three dark brown 

 spots, situated at the origin of Rs and along the cord; abdomen 

 reddish brown, the lateral margins of the tergites darker; apices 

 of the ninth sterno-pleurite of the male hypopygium produced into 

 slender spatulate blades. 



Male. — Length 26.5 mm.; wing 22 mm.; abdomen alone, 18.5 mm. 



Frontal prolongation of the head brown; palpi dark brown. An- 

 tennae with the scape and pectinated flagellar segments pale yellow- 

 ish brown, the terminal flagellar segments dark brown, flagellar 

 pectinations pale, a very little longer than the segments that bear 

 them. Head reddish brown; vertex between the eyes very narrow, 

 as in the genus. Mesonotum light brown, the praescutum with four 

 very slightly darker, indistinct stripes; median area of the scutum, 

 scutellum and postnotum dark brown. Pleura light brown, sparselj^ 

 pruinose. Halteres dark brown. Legs with the coxae pale brown- 

 ish yellow; trochanters light yellow; femora brownish yellow, the 

 tips broadly and conspicuously brownish black; tibiae brownish 

 yellow, the tips narrowly dark brown; tarsi dark brown. Wings 

 with a very strong reddish brown tinge, more saturated in the 

 costal and subcostal cells; base of the wing, in the anal cells, pale, 

 three dark brown spots arranged as follows: a small one at the 

 origin of Rs; a large blotch along the cord, extending from the fork 

 of Rs to the fork of M; the third spot is slightly smaller than the 

 last, at the fusion of Cui and Mz; stigma pale brownish yellow; 

 veins brownish yellow. Venation as in the genus ; tip of Ri atrophied ; 

 tip of Ro semiatrophied, pale; fusion of Cui and Ms about equal 

 to r-m. Abdomen dark reddish brown, the lateral margins of the 

 tergites broadly darker brown, narrowly interrupted at the caudal 

 margins of the segments; sternites brownish yellow. Male hypo- 

 pygium with the sterno-pleurite produced caudad into slender spatu- 

 late blades that are subequal in length to the outer pleural append- 

 age. 



