STRATIOMYIDTR. 47 



3. Anterior ocellus more widely separateil tlian the other two; males lio- 



loptic or dichoptic. 4 



Ocelli equidistant, more approximated 5 



4. Abdomen contracted near the base, clavate or pedicillate. 



Mackosargus Bifjot. 

 Abdomen not pedicillate or clavate. . . . Sargus Fabricius. 



5. Second antennal joint prolonged on the inner side, extending on and 



closely lying upon the third joint. . . . Ptecticus Loew. 



Second antennal joint not with such a projection 



G. Hind femora moderately thickened on tlie proximal portion ; origin of 

 the second vein near the anterior cross-vein (Central and South 

 America) Merosargus Loew. 



Hind femora slender, or the second vein remote from the anterior cross- 

 vein. ............ 7 



7. Tliird joint of tlie antennte pointed, the arista somewhat thickened ; first 



antennal joint moderately long (Central and South America). 



HiSTiODROMA Schiner. 

 Tlurd antennal joint oval, the arista slender. . .... 8 



8. Elongate species ( C/»-ysono/«s preoc.) . Chrysochroma, nom. nov. 

 Deep metallic species; abdomen short; eyes of male with an area of 



enlarged facets above; front of female broad. Microchrysa Loew. 



STRATIOMYIIs^E. 



1. Third longitudinal vein with an anterior branch ; tliird joint of anteimsw 



elongate .2 



Tliird longitudinal vein without anterior branch G 



2. Scutellum without spines ; first two joints of tlie antennae short (Central 



and South America). . . . Ciiordonota Gerstiecker. 



Scutellum with spines, rarely wanting in Odontomyia. . . . o 



3. Third joint of the antenn:e composed of from three to five annuli. 4 

 Tliird joint composed of seven or eight annuli o 



4. First antennal joint three or four times the length of the second. 



Stratiomvia GeolTroy. 

 First antennal joint less than tliree times tlie length of the second. 



Odontomyia Meigen. 



0. Third antennal joint elongate, terminating in a point ; first joint two or 

 three times tlie length of tlie second ((!eiitral and Soutli America and 



West Indies) Cyi-iiomyia Wiedemann. 



Third antennal joint terminating in a bristle; first joint but little longer 

 than the second (Central and South America). 



Nkorondania Osten Sacken. 



