1910] Melaniler — The Genus Tachydromia 49 



Genera and Subgenera of the Tachydromiiai. 



Thorax slender, humeri large, strongly constricted: palpi narrow: legs not 

 bristly: front femora thickest. 

 First basal cell much shorter than the second : black species. 



Anal cell present: arista terminal Tachypeza Meigen. 



Anal cell completely wanting. 



Arista terminal or sub-terminal : marginal cell long. 



Tachydromia Meigen. 

 Arista sub-dorsal: second vein abruptly recurved. 



Phoneutisca Loew. 

 First basal cell longer than second; outer angle only of anal cell present: 



yellow species Dysaletria Loew 



Thorax broad: humeri rarely large: legs hairy and usually with bristles: 

 palpi usually broad. 

 First basal cell shorter than second: eyes close together, especially below 

 the antennae. 

 Arista terminal. 



Anal cell complete or incompletely formed. 



Front and middle femora thickened: middle femora with a double 

 row of spines beneath: middle tibiae ending in a spur: eyes 



separated: palpi broad Platypalpus Macquart. 



Last joint of tarsi normal Platypalpus s. sir. 



Last joint of anterior tarsi greatly lengthened. 



Cleptodromia Corti. 



Femora not thickened : middle legs without spurs and with minute 



or no spines: eyes contiguous: palpi small: basal cells subequal. 



Symballophthalmus Becker. 

 Anal cell wholly wanting: posterior femora more or less thickened. 



Drapetis Meigen. 

 Body robust, abdomen shorter than thorax: Wings broad, not 

 ciliate. 



Third antennal joint short-oval Drapetis s. str. 



Third antennal joint lanceolate Elaphropeza Macquart. 



Body more slender: abdomen longer than thorax: wings cuneiform: 



costa long ciliate Ctenodrapetis Bezzi. 



Arista dor.sal: front femora thickened Stilpon Loew. 



First basal cell equal to or longer than second: more or less opaque pollinose 

 species: eyes usually widely separated on the face. 

 Arista dorsal. 



Wings less than one-third the abdomen Thinodromia Melander. 



Wings surpassing the abdomen, anal cell faint . . . Halsanalotes Becker. 

 Arista terminal. 



Antennae three-jointed: legs thick and bristly: eyes very small. 



Coloboneura Melander. 



Antennae two-jointed: legs but little thickened and with few bristles, 



face narrow Chersodromia Walker. 



