26 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 69 



Genus XYLOTA Meigen, sensu stricto 



The Xylotae proper, represented by the genotype Xylota segnis 

 (Linnaeus), are characterized by: Metasternum with faint pubes- 

 cence which is very much shorter than the length of the pile on 

 hind coxae; head broadly elliptical; metathoracic spiracle as large 

 or larger than third antennal joint; arista usually longer than width 

 of face at middle; hind femora usually fairly slender; male with 

 frontal triangle covered Avith silvery pollinosity (except viri- 

 daenea) ; hind trochanter with spur (except hicolor) ; fore basitarsus 

 with a long light-colored hair on inner apical corner; ventral sur- 

 face with short black spines near base. Female : Front rather 

 narrow. 



In the following key scutellarniata Lovett has been omitted. 



KKY TO THE SPECIES OF XYLOTA, SBiNSU STRICTO 



(Metasternum faintly pubescent; type, Xylota segnis (Linnaeus)) 



A\ Arista pubescent ; antenna black ; second and third tergites chiefly reddish 

 or yellowish brown. 



B*. Second and third tergites with median dark line subfasciata Loew. 



B^ Second and third tergites without median line notha Williston. 



A'. Arista bare. 



B\ Abdomen largely purplish red; legs entirely reddish brown. 



rufipes Williston. 

 B*. Abdomen not purplish red. 



C\ Abdomen chiefly reddish orange beyond first tergite, rarely dark- 

 ened apically (see segnis). 

 D\ Hind tibia entirely black; arista longer than width of face; 

 abdominal pile entirely white and yellow ; male without spur 



(eastern species) bicolor Loew. 



D^ Hind tibia yellow at base ; arista about as long as width of face ; 

 male with spur, always? (western species). 



E\ Hind tarsi mostly bright yellow flavitibia Bigot. 



E^ Hind tarsi entirely black argoi, new species. 



C^. Abdomen black, second and third tergites may have more or less red- 

 dish or yellowish color. 

 D\ Second and third tergites brassy red ; mesonotum green aeneous ; 

 ocelli placed well forward of occipital margin of eyes. 



segnis (Linnaeus). 

 Dl Second and third tergites not brassy red, but with or without 

 yellowish spots. 

 E\ Abdomen with fourth tergite bright metallic green ; second 

 tergite with pair of brassy yellow spots. 



F'. Arista shorter than width of face analis Williston. 



F^ Arista longer than width of face. 



G\ Face yellow ; antennae black ; third tergite without 



yellow spots nebulosa Johnson. 



G^ Face black; antennae yellow; third tergite with yel- 

 low spots viridaenea, new species. 



