1921] NATURAL SCIENCES OF PHILADELPHIA. 79 



Gonomyia (Leiponeura) falcifer sp. n. Plate IV, fig. 2. 



Belongs to the cinerea group; male hypopygium with three pleural 

 appendages, the ventral appendage elongate, falcate, on its proximal 

 face near the base with two erect spines; dorsal appendage a small, 

 pale, setigerous lobe; penis-guard and gonapophyses without con- 

 spicuous chitinized parts. 



Male. — Length about 3.5 mm.; wing 3.8 mm. 



Generally similar to G. (L.) acuminata sp. n., differing as follows: 

 Posterior lateral margins of the mesonotal scutum more distinctly 

 yellowish. Fore legs present in the type; femora dark brown with 

 only the bases narrowly paler. Wings with Rs a little straighter. 

 Male hypopygium (Plate IV, Fig. 2) conspicuously different from 

 any described species. The pleurites are a little longer than in 

 acuminata; pleural appendages only three in number; the longest 

 or ventral of these is broad basally and here produced on the prox- 

 imal face into two short, subacute spines that are directed caudad, 

 one of these blackened and with the margin weakly serrulate, the 

 other spine a little longer, pale, only the acute tip a little darkened; 

 the outer or lateral face of this appendage runs caudad into a long, 

 moderately slender curved point that is approximately as long 

 as the pleurite itself, the tip obtusely and indistinctly recurved, 

 the inner margin weakly serrulate; the intermediate pleural append- 

 age is a small, flattened blade, pale at the base, the tip produced 

 into two conspicuous blackened spines; the third or dorsal appendage 

 is a small, roughly subglobular lobe, pale, provided with about 

 ten conspicuous setae. Penis-guard and gonapophyses pale with 

 few evident chitinized parts; the gonapophyses appear as two pale 

 cushions that are microscopically setigerous. 



Habitat. — Peru. 



Holotype, d", Yurimaguas, April 13, 1920 (H. S. Parish). 



Gonomyia (Leiponeura) machaeria sp. n. 



Closely related to G. helophila Alexander; male hypopygium with 

 the ventral pleural appendage sword-like, the basal half dilated; 

 dorsal appendage entirely fleshy with a small, oval, glabrous lobe 

 at its base; no intermediate appendage. 



Male. — Length about 3.2 mm.; wing 3 mm. 



Rostrum and palpi dark brown. Antennal scape orange; flagel- 

 lum broken. Head brown, paler behind. Pronotum light yellow. 

 Mesonotal praescutum gray with four narrow, brown, longitudinal 

 stripes, the intermediate pair longer and almost confluent; scutal 

 lobes brown; scutellum and postnotum light gray pruinose. Pleura 

 dark brown, with a broad white longitudinal stripe, beginning im- 

 mediately behind the fore coxae, passing ventrad of the halteres 

 to the base of the abdomen ; dorsad of this conspicuous white stripe 

 is a very narrow and less distinct silvery-gray stripe that branches 



