STRATIOMYIDJE. 47 



3. Anterior ocellus more widely separated than the other two ; males ho- 



loptic or dichoptic 4 



Ocelli equidistant, more approximated ' . . 5 



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



MACKOSARGUS Bigot. 

 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. .... 6 



6. Hind femora moderately thickened on the 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. Third joint of the antennae pointed, the arista somewhat thickened ; first 



antennal joint moderately long (Central and South America). 



HISTIODROMA Schiner. 

 Third antennal joint oval, the arista slender 8 



8. Elongate species ( Chrysonotus 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. 



STRATIOMYINJE. 



1. Third longitudinal vein with an anterior branch ; third joint of antennas 



elongate , . . . . . 2 



Third longitudinal vein without anterior branch 6 



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



and South America). . . . CHORDONOTA Gerstaecker. 



Scutellum with spines, rarely wanting in Odontomyia. ... 3 



3. Third joint of the antennae composed of from three to five annuli. 4 

 Third joint composed of seven or eight annuli 5 



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



STRATIOMYIA Geoffroy. 

 First antennal joint less than three times the length of the second. 



ODONTOMYIA Meigen. 



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



three times the length of the second (Central and South America and 

 West Indies). . . . . CYPHOMYIA Wiedemann. 



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

 than the second (Central and South America). 



NEORONDANIA Osten Sacken. 



