Tachinidae. 53 



used, and his system has been accepted and is used in Kat. d. palåarkt. 

 Dipt. by Bezzi, who has made a very troublesome work in arranging 

 the palæarctic genera and species according to it. I exchide here Eginia, 

 which I think does not belong here, and I include Gastrophilinae, 

 as I think they are, in spite of the wanting hypopleural bristles, 

 related to the other Oestrid forms. In 1924 Villeneuve has pubhshed 

 an important paper about the systematic (Ann. d. Se. Nat. Bot. et 

 Zool. 10, VII, 1924, 5); the author makes use of Girschner's groups, 

 but alters to some degree their conception (the Dexiinae are reduced 

 and about in the sense of Schiner, the Rhinophorinae are extended, 

 comprising more genera, and Ocyptera is placed to Phasiinae etc), 

 and herein I quite follow him. The Tachinidae he divides into two 

 groups, Protachininae and Eutachininae^ the former including the 

 less developed forms, the latter the most developed and highest 

 standing. This latter group he again divides into tliree smaller groups, 

 according to his prevertical bristle (the uppermost, generally some- 

 what outwards placed frontal bristle) being reclinate or transverse 

 and present only in the female or in both sexes. Villeneuve draws 

 in the paper attention to many interesting characters, and perhaps 

 his arrangement is the most natural hitherto. I have therefore also 

 resolved to make use of it here, though I must premise that the 

 study of our comparatively small fauna has not made it possible 

 for me fully to judge about the value of it. The Tachinidae are no 

 doubt the youngest and most developed group of flies, which also 

 their biology indicates (though de Meijere thinks the Holometopa 

 younger than the Schizometopa). They seem to be in rapid develop- 

 ment, and therefore the systematic is so difficult. The characters 

 are so many and so varied, and this is just the cause why so many 

 genera have, one may say necessarily, been erected. When it was 

 begun to divide the old larger genera, it was, so to say, impossible 

 to stop before nearly every species had become a genus, and the reduc- 

 tion again was difficult, a midway is not easily found. It also can not 

 be denied that many genera are very restricted, much more so than 

 genera in other families. The said facts have also given rise to the 

 synonymy being very complicated and confused. In the limitation 

 of the genera and the use of the generic names I mainly follow the 

 catalogue, though I am aware that several names will no doubt 

 have to be altered; also the circumscription of the genera will no 

 doubt in the future necessarily undergo many alterations, but the 

 small fauna, I have worked with, has not made it fortunate to do 

 anything in this direction. 



