Dec, I9I5-] Banks: Notes on Platypeza. 213 



NOTES ON SOME VIRGINIAN SPECIES OF 

 PLATYPEZA (PLATYPEZIDAE, DIPT.) 



By Nathan Banks, 

 Washington, D. C. 



About five or six species of this genus have been recorded from 

 the Eastern States, one of which (P. pallipcs), goes in the genus or 

 subgenus Calotarsa. Of the others there are few records. I have 

 collected several local species and in identifying them find that five 

 are new ; several others may represent new species. There is some 

 sexual dimorphism in the genus, so I have based the new species only 

 on males. Johnson has claimed this dimorphism in P. pallipcs, and 

 what I consider the female of P. flavicornis differs radically in the 

 abdominal markings and color of the halters from the male. 



The species known to me are separable as follows : 



Males 



1. Posterior cross-vein fully its length from the hind margin 2. 



Posterior cross-vein not its length from the hind margin ; submedian rows 



of fine bristles on the mesonotum ; hind tarsi black 5. 



2. Abdomen wholly velvety black above 3. 



Abdomen not wholly velvety black above 4. 



3. Antenna yellowish ; fourth vein plainly bent down a little before the pos- 



terior cross-vein ; third section of fourth vein much longer than fourth 



section of fourth vein flavicornis. 



Antennae dark; fourth vein not bent down before posterior cross-vein; third 

 and fourth sections nearly subequal minorata. 



4. Abdomen shining above, no spots on the segments nitida. 



Abdomen with three pale pollinose spots on fourth segment . . . .suhmacula. 

 Abdomen with velvety black median spots on fifth and sixth segments. 



mediana. 



5. Abdomen with gray marginal spots tcrniata. 



Abdomen black, unspotted 6. 



6. Abdomen broadly rounded ; costal cell extending far beyond end of first 



basal cell velutina. 



Abdomen elongate; costal cell extending only a little beyond end of first 

 basal cell elongata. 



Females. 



I. Posterior cross-vein not its length from the hind margin 2. 



Posterior cross-vein fully its length from the hind margin 3. 



