Vlll 



Keys to families: — 



Larvae 308 



Pupae 310 



Imagines 312 



Tribe Platygenya 314 



Stratiomyioidea 314 



Stratiomyiidae 315 



Key to subfamilies 316 



Stratiomyiina? 317 



Clitellariinae 322 



Beridinae 331 



Geosarginae 331 



Pachygasterinas 334 



Xylomyiinag 340 



Principal papers on North American Stratiomyiidae 346 



Xylophagidae 346 



Coenomyiidae 351 



Acanthomeridae 354 



Tabanoidea 354 



Tabanidae 355 



Principal papers dealing with the biology of North Amer- 

 ican Tabanidae 361 



Leptidae 362 



Cyrtoidea 368 



Xemestrinidae 368 



Cyrtidae 368 



Papers on North American Cyrtidae 369 



Asiloidea 369 



Mydaidae 370 



Apioceridae 373 



Asilidae 373 



Bombyliidae 389 



References to Descriptions of larvae and pupae of North 



American Bombyliidae 395 



Therevoidea 396 



Therevidae 396 



Scenopinidae 398 



Tribe Orthogenya 399 



Empididoidea 399 



Empididae 400 



Papers on the biology of North American Empididae 403 



Dolichopodidae 403 



References to papers on the biology of North American and 



European Dolichopodidae 406 



