February issue includes Appendix entitled Directory of United States Government periodicals and subscription publications; September issue includes List of depository libraries; June and December issues include semiannual index

While volume 1 includes several introductory chapters and treats 42 families of flies in the Lower Diptera, volume 2 covers the remaining 64 families of flies that make up the Higher Diptera (or Cyclorrhapha). These include families of house flies, fruit flies, bot flies, flower flies and many other lesser-known groups. The text is accompanies by over 1660 line drawings and photographs.