FAMILY STRATIOMYID.E THE SOLDIER FLIES 145 



56. Third vein with a branch near the end of the first vein 57 



Third vein without the basal branch (77) Aloipha Enderlein 



57. Second antennal segment subtriangularly produced into the third on the 



inner side (15, 16, 39) Ptecticus Lcew 



Second antennal segment at most moderately convex on its inner end, 

 never subtriangular (18, 63) *Merosargus Loew 



58. Ocellar triangle situated far from the vertex and almost or quite twice 



as long as wide ( 14, 88 ) Pedicella Bigot 



Ocellar triangle not or but little longer than wide, in the female partly 

 behind the upper angles of the eyes, in the male usually somewhat in 

 front of this point 59 



51). Ocellar triangle in female lying almost all in front of the posterior 

 angle of the eyes, the males without the eyes divided into definite 

 zones of differently sized facets; anal cell much narrower than the 



combined basal cells (45, 89) Chrysochroma Williston 



Ocellar triangle in female lying mostly behind the posterior angles of 

 the eyes; males with the facets enlarged on the upper half; anal cell 

 quite as wide as the combined basal cells (29, 48) . . . .Microchrysa Loew 



* Curran, 1932. Amer. Mus. Novit. No. 534. 



