FAMILY TACHINID.^ — THE TACHINIDS 419 



genus known to me. No one can correct the classification of this family 

 without a very large collection from all parts of the world and a very 

 extensive study will be necessary before any satisfactory generic limita- 

 tion can be fixed. Indeed, the classification can never be settled because 

 we are continually discovering new connecting links between genera 

 and species. Some genera are well established and fairlv well limited 

 but the number is small. 



It is unfortunate that Dr. C. H. T. Townscnd has been unable (up 

 to the present time) to find a publisher for his volumes on the classifica- 

 tion of this family. No one has ever equalled Townsend in knowledge of 

 the Tachinidas and liis keys would prove to be of inestimable value and 

 would throw light on the position of the hundreds of genera described 

 in various places. At the present time one is absolutely lost unless speci- 

 mens are availa])lc, and it is only by chance that an occasional specimen 

 can be determined. 



The student will find a number of changes in nomenclature incor- 

 porated in this work and I fear that this will cause some confusion. 

 However, due to the work of Townsend and others we have now dis- 

 covered older names for many of our species and genera and many 

 misconceptions in identification have been corrected. It is suggested 

 that, if a name occurs in literature and cannot be found in the key, it 

 be looked for in the index. In this way most of the names will be found. 

 Nevertheless, there will be confusion because most of the older authors 

 had little conception of the position of the species described and many 

 very different forms have been placed in the same genus. Things are 

 not quite as hopeless as they may seem, but the beginner will find him- 

 self badly handicapped, at least until a catalogue is published. 



A preliminary key has been prepared in order to obviate the neces- 

 sity of going through the entire key and turning many pages before 

 arriving at suitable couplet. Any figures on the right of the page of 

 the abbreviated key refer to a couplet in the key proper and the search 

 for the genus sliould be taken up from that point. 



SYNOPTIC TABLE OF KEY GROUPS 



A. Lower lobe of sciuamse bare above T> 



Lower lobe of squamae pilose above 2 



B. Middle of propleura bare C 



Middle of propleura with pile or hair 4 



C. Infrasquamal setulae absent; abdomen with bristles E 



Infrasquamal setulae present or the abdomen without dorsal bristles. . D 



D. Eyes haired 55 



Eyes bare or almost so 84 



