STRATIOMYID^E. 



169 



SARGIN^S. 



11. Scutelluni with spines. ........ 12 



Scutelluni without spines. . . . . . . .14 



12. Third vein with anterior branch (fig. 54; 31). Rhaphiocera. 

 Third vein without anterior branch. ..... 13 



13. Scutelluni produced into a stout median process, bearing two di- 



varicate spines at its tip (36). Dicranophora, S. A. 

 Scutelluni with marginal spines. . . . Nothomyia. 



14. Second longitudinal vein coalescent with the first in a broad ex- 



pansion of the costa; antennae moderately long, the long arista 



flattened (19) Histiodroma. 



Wings not with an anterior distal expansion of the costa. . 15 



15. Anterior ocellus more widely separated than the other two; males 



holoptic or dichoptic. . . . . . . . 16 



Ocelli equidistant, more approximate. ..... 17 



16. Abdomen contracted at its base, clavate or pedicillate 



Macrosargus*. 

 Abdomen not clavate or pedicillate (14) {Sargus) . Geosargus. 



17. Second antennal joint prolonged on the inner side, closely over- 



lying the third joint (fig. 56, 15, 16) . . Ptecticus. 



Second antennal joint not with such a projection. . . 18 



18. Third joint of antennae elongate, composed of four segments, with 



a long terminal arista thickened and pubescent at its base. 



Acrochseta. 



Third antennal joint short, oval or subulate, with an apical or pre- 



apical arista. . . . . . . . . . 19 



19. Hind femora moderately thickened at base; non-metallic, more or 



less yellow species (18) ..... Merosargus. 

 Hind femora not more thickened at base; usually blue, green and 



metallic species, elongate. . . . Chrysochroma. 



Hind femora slender; small, deep-colored species; the holoptic eyes 



of the male with an area of enlarged facets above; eyes hairy 



{Myiochrysa)\ or bare (29). . . . Microchrysa. 



STRATlOMYINi£. 



20. Third vein with an anterior branch. ..... 21 



Third vein without anterior branch; scutellum spinose. . 28 



* The genus Macrosargus is so feebly differentiated that I do not 

 think it can be maintained. If not, the name must take preference 

 over Cieosargus bezzi, substituted for Sargus, preoccupied. 



