294 ENTOMOLOGICAL N'F.VYS |xxxii.'21 



turn more reddish brown ; ovipositor with the elongate valves horn- 

 colored. 



Holotvpc : $ , Punta cle Balasto, Catamarca. altitude 2,300 

 meters, November 10, 1920 (V. Weiser). AUotopotypc: 9, 

 November 11, 1920. Paralypcs: H, 3?'s, Santa Maria, Cata- 

 marca, October 30, 1920 (V. Weiser) ; 1$, 1 9 , Rio Diamante, 

 southern Mendoza, January, 1921 (Dr. Carette) ; 60 $ 9, 

 P.anado, Valle de Santa Maria, Tucuman, April 2-11, 1921 

 (V. Weiser). 



Rhabdoinasti.v basalis is an exquisite little fly that is con- 

 spicuously different from all described members of the genus. 



Gcnomyia (Leipcneura) adunca sp. n. 



Antennal scape yellow; head yellow, the vertex with a large brown 

 area; thoracic pleura striped longitudinally with silvery white and dark 

 brown ; wings yellowish gray, stigma inconspicuous ; Sc short, Sc2 at tip 

 of Sc\ ; Rs short, arcuated at origin; cell 1st M2 closed; abdominal ter- 

 gites brown, paler caudally ; sternites whitish with a conspicuous brown 

 lateral line ; male hypopygium with three pleural appendages, of which 

 only one is chitinized, the apex curved, acute. 



$ . Length about 3.8 mm. ; wing 3.6 mm. 



Rostrum and palpi dark brown. Antennae with the scapal segments 

 yellow, the flagellum dark brown. Head pale whitish yellow with a 

 large, dark brown area on vertex. 



Pronotum yellowish white, narrowly dark brown medially. Mesonotal 

 praescutum dark brown, the humeral region brighter, the lateral mar- 

 gins to the wing-root narrowly but conspicuously whitened ; scutum 

 brownish yellow, the center of each lobe and the capillary median line 

 darker brown; scutellum obscure brownish yellow, sparsely pruinose, 

 darker brown medially ; postnotum pale, gray pruinose, the posterior 

 margin with two dark brown spots. Pleura dark brown with a broad 

 and conspicuous silvery white stripe from the fore coxa to the base of 

 the abdomen ; a narrow brown line extending from the cervical sclerites 

 to the postnotum, passing beneath the base of the halteres ; posterior 

 dorsal pleurites pale, anterior dorsal pleurites infuscated. Median area 

 of mesosternum pale. Halteres pale yellow, the knobs dark brown. Legs 

 with the coxae pale white or testaceous ; trochanters yellow ; femora 

 light brown, the tips indistinctly darkened ; tibiae brown, the tips nar- 

 rowly darkened ; tarsi brown. Wings with a faint yellowish gray tinge ; 

 stigma slightly darker, but still very pale; cord and outer end of cell 

 1st M2 indistinctly seamed with darker; veins brown. Venation: Scl 

 short, ending far before the origin of Rs, Sc2 at the extreme tip of Scl ; 

 Rs short, only a little longer than the deflection of 7^4+5, strongly arcu- 



