64 PROCEEDINGS OF THE ACADEMY OF [Part I 



yellow, passing into dark brown before the tip of the organ. Head 

 obscure yellow with a delicate brown median hne. Mesonotal prae- 

 scutum yellowish brown with three darker brown stripes; median 

 stripe pale anteriorly but becoming better defined toward the su- 

 ture; lateral margins and a capillary median vitta darker brown; 

 lateral stripes brown, their cephalic ends directed proximad, indis- 

 tinctly confluent with the median stripe, isolating two pale sub- 

 median areas immediately before the suture; scutum brown, each 

 lobe with a brownish yellow circle, enclosing a dark center; scutellum 

 and postnotum brown. Pleura obscure yellow with a relatively 

 narrow dorsal brown stripe; mesosternuni also brown, these two 

 dark areas enclosing between them an ill-defined longitudinal pale 

 stripe. Halteres with the stem yellow^, the knobs dark brown. 

 Legs wdth the coxae and trochanters obscure yellow ; femora yellow- 

 ish, before the tips with a narrow, subterminal brown ring; tibiae 

 yellow, the extreme bases narrowly infuscated, the tips narrowly 

 dark brownish black; tarsi obscure yellow^, the terminal segments 

 slightly darker. Wings with a strong brownish yellow tinge, the 

 costal cell more brownish, the subcostal cell clear yellow; darker 

 brown clouds at the base of cell R; at origin of Es; fork of Rs and 

 at the stigma; all the veins are very broadly seamed with greyish, 

 these seams restricting the ground-color to narrow longitudinal 

 streaks; basal third of cell Ro yellow, the distal two-thirds greyish; 

 veins brown. Venation: Sci ending immediately beyond r; Rs 

 long, strongly angulated at origin, a httle longer than Ri+3; R2 

 subcontiguous with Ri at costa so that cell 2nd Ri has an elongate- 

 triangular shape; petiole of cell Mi a little shorter than the basal 

 deflection of ^4 + 5; m about one-half the outer deflection of M3; 

 Cui shorter than the basal deflection of Cwi. Abdominal tergites 

 brown, each segment slightly paler basally; sternites yellow. 



Habitat. — Peru. 



Holotype, 9 , Yurimaguas, April 6, 1920 (H. S. Parish). 



By means of the author's key to the species of the genus Psoronius 

 (Trans. Amer. Ent. Soc, vol. 40, p. 250. 1914), P. triangiilifenis 

 runs out to couplet 3, both of the included species having the meso- 

 notum practically unicolorous. From the more recently described 

 P. pallipes Alexander (Brazil), the present species differs in the 

 venation and the coloration of the tarsi. 



Psaronius mancus sp. n. 



Mesonotal praescutum brownish yellow with three darker brown 

 stripes, the median stripe with a capillary darker brown line that 

 continues back to the base of the abdomen; femora wdth a narrow 

 subterminal brownish black ring; tibiae light brown, the base and 

 tip blackened; wings brownish yellow, the veins conspicuously 

 seamed with brown; vein R2 entirely lacking; cell Mi shorter than 

 its petiole. 



Female.— Length 21-22 mm.; wing 14.2-15 mm. 



