NO. 1227. ARRANGEMENT OF THE DIPTERA—COQUILLETT. 655 



have not yielded altogether sati.sfactoiy re.'^ults. TIk^ impossibility of 

 indicatino- natural relationship by a linear arrangement is, of course, 

 well understood. The following arrangement, which is a moditica- 

 tion of the systems of Latreille and Schiner, with suggestions of Osten 

 Sacken and "Willi.ston, will, it is believed, serve to indicate the natural 

 relationships of the various families in a clearer manner than any of 

 those that have lieen thus far proposed: 

 Suborder Proboscidea Latreille. 

 Section Orthorhapha Brauer. 

 Subsection Xemocera Latreille. 



Superfamily Tipulotdfit Coquillett. 



Families: 1 Tipulida-, 2 Dixidje, 3 Culicidic, -i Psychodidre, 

 5 Stenoxenidiv, 6 Chironomidiv, T Cecidomyida% 8 Myceto- 

 philida?. 

 Superfamily Blhlonoldea Coqu.illett. 



Families: 9 Bibionidiv, 1<> Sinuilida^, 11 Orphnephilidaj, 12 

 Blepharocerida?, 13 lihyphidte. 

 Subsection Bracliycera ^Nlacquart. 

 Superfamily Tabanoidea Coquillett. 



Families: 14 Leptid.T, 15 Stratiomvida?, 10 Acanthomeridfe, 

 IT Tabanidffi, IS Acroceridw, 19 Kemestrinida?. 

 Superfamih" Bomhylioidta Coquillett. 



Families: 20 Apioceridic, 21 Mydaidte, 22 Bom])ylidie. 

 Superfamily Ai<!I<>!dca Coquillett. 



Families: 23 Scenopinidre, 21 There vid;\?, 25 Asilidfe, 26 

 Empidi¥, 27 Dolichopodida'. 

 Superfamily Phoroidea Coquillett. 



Families: 28 Lonchopterida^, 29 Phorida?. 

 Section Cvclorhapha Brauer. 



Superfamily SyrjdiO'dia Coquillett. 

 Families: 30 Platypezida\ 31 Pipunculido?, 32 Syrphidae, 33 

 Conopidffi. 

 Superfamily Jfuscoidea Coquillett. 

 Group Caly2)teratae Desvoidy. 



Families: 31 Oestrida% 35 Tachinida?, 36 Dexida^, 37 Sarco- 

 phagidaj, 38 Muscida% 39 Anthomyidre. 

 Group Acalypterae Macquart. 



Families: 40 Scatophagida, 11 Heteroneurida^ 42 Helo- 

 niA^zida?, 43 Phycodromida^, 44 Sciomyzidas, 45 Sapro- 

 myzida, 46 Lonchfeida^, 47 Ortalidse, 48 Trypetida?, 

 49 MicropezidfB, 50 Sepsidty, 51 Psilidw, 52 Diopsida?. 

 53 Ephydrida?, 54 Oscinidte, 55 DrosophilidiB, 56 Geom- 

 yzida, 57 Agromvzida^, 58 Borboridfe. 

 Suborder Eproboscidea Latreille. 



Families: 59 Hippoboscida, 60 Nvctiu-ibida. 



