fomora darkened; upper surfaees of femora witli wliitish appressed 

 soales ; abdomen black with a white transverse stripe at anterior margin 

 of seeond tergite ; first terji'ite with white pile whieh overhangs the 

 white stripe of the seeond tergite; wings hyaline with a dark stigma ; 

 petiole beyond the anal eell equal to one and one-híilf times the length 

 of the anterior cross-vein ; halteres yellow. 



Five males collected in shady woods. 



Type locality: — Quebrada de Lules, Tueuman (2.2.27, E. Del- 

 Ponte and R. C. Shannon). Also from Tafi Viejo, Tueuman, (14.3.27, 

 Del Ponte and Shannon). 



Named for Doctor Eduardo Del Ponte, entomologist of the Insti- 

 tuto Bacteriológico. 



SUBORDER CYCLORRAPHA 



Series Afhericera 



Secfion Asdiiza 



Family Plafypezidae 



Small, thinly pilóse flies with few bristles and with the hind tarsi 

 dilated ; arista placed at the apex of the third antennal joint. The 

 larvae live in fungi. 



Three species of this family representing two genera, Platypeza 

 and Agathomyia, have been found in the Province of Tueuman. The 

 genera may be separated as follows. 



Platypeza: — ■ Third antennal joint as long as broad ; last section 

 of fourtli vein with a distinct angle, the terminal portion directed 

 towards the third vein but does not joint it. 



Agathomyia: — Length of third antennal joint distinetly longer 

 than its base, and strongly tapered ; fourth vein straight 



Genus Platypeza Meigen 



The two species at hand may be separated as follows : 

 Platypeza tJiomseni: Length of the preangular section of the 

 fourth vein (between the posterior crossvein and the angle at its 

 apical section) is twice the length of the posterior crossvein. 



Plaiypeza tucumana: Length of the preangular section of the 

 fcurth vein approximates the length of the posterior crossvein. 



Platypeza thomseni, new species 



Male: — Of average size (3 mm., wing 2.5 mm.) with very large 

 eyes (purlish red in life) body of a black, velvety appearance. 



Head: ■ — Ocellar triangle black, elevated and equal sided ; eyes 

 broadlj'- contiguous above and with enlarged facets; on the lower 

 portion of the eye the facets are much smaller and darker : antennae 

 small, black, the arista very elongate ; face black, with a f aint grayish 

 pruineseence and without hairs; palpi dark. 



Thorax: — Mesonotum with scattered, small setae and prominei^t 

 bristles located as follows : one anterior sublateral ; three notopleurals ; 



