36 DIPTERA OP NORTH AMERICA. [PART 111. 



4. HYPOTYPHLA Lw. ; 5. TOXOTRYPANA Gerst. ; 6. SPHENOPRO- 

 SOPA, Lw. ; 1. BROMOPHILA, Lw. ; and 8. DICHROMYIA, R. Desv. 

 The final decision about the location of Toxotrypana, Bromo- 

 phila, and Dichromyia is, of course, reserved. 



The characters common to these eight genera are : oral open- 

 ing small ; proboscis not incrassated ; clypeus but little developed ; 

 no bristle upon the broad cheeks, and no bristle immediately 

 over the fore coxae ; the first longitudinal vein hairy ; the costal 

 vein soon attenuates beyond the end of the third longitudinal 

 vein. The ovipositor is not flattened. 



Second Section : Platy stamina. 



The name of this section is derived from Platystoma Meig., 

 the oldest and best known genus in it. 



PLATYSTOMA is represented in Europe by a number of closely 

 allied species which must be considered as typical. We may 

 entertain different views on the extent of the genus Platystoma, 

 still we would not be justified in introducing in it, as has often 

 been done, species which, in the majority of the most important 

 characters, differ from the European Platystomse. In fact, most 

 of the exotic species, described by different authors as belonging 

 to Platystoma, 'do not belong to it at all. 



The Dictya decora Fabr., identical with Tephritis violacea 

 Gray, and placed by Wiedemann among the Platystomse, has the 

 posterior angle of the anal cell drawn out into a long lobe ; this 

 character at once distinguishes this species, not only from Platy- 

 stoma proper, but from all the genera closely related to it. Mac- 

 quart was right in establishing the new genus LOXONEURA for it. 

 Walker afterwards called it Zona. Judging from the figure of 

 the head of Loxoneura decora, in profile, given by Macquart in the 

 Dipteres Exotiques, this genus must belong to the Platystomina; 

 the absence of the pro- and mesothoracic bristles, and the only 

 four-jointed abdomen of the female confirm the correctness of 

 this location ; the fore femora are spinous. 



Whether the South-American Platystoma stictica Fab. really 

 belongs to Platystoma is very doubtful. 



Only a few of the species, placed by Macquart in the genus 

 Platystoma really belong there, for instance, none of his Ameri- 

 can species. Platystoma fascipennis and ocellata are Ortalidse, 

 but belong to the Pterocallina, not to the Platystomina. Plaly- 



