64 R. W. CROSSKEY 



abdomen often with discal setae (discals present on T3, T4 and T5 in both Australian genera) ; 

 sternites concealed. 



Attention should be called to the spelling of the generic name Halydaia. This 

 name in Tachinidae is usually spelled Holiday a, and this is reasonable from a 

 common-sense point of view since the genus was named in honour of the dipterist 

 Haliday. However, Egger (1856) was apparently under the impression that 

 Haliday's name was spelt as 'Halydai' as he wrote Teh habe sie zu Ehren des 

 englischen Dipterologen A. H. Halydai Halydaia genannt', and nowhere in the 

 original description does the spelling Haliday or Halidaya appear. In this curious 

 circumstance it is open to question how Article 32 (a) of the International Code of 

 Zoological Nomenclature, 1961, applies, but Halydaia is held here to be a correct 

 original spelling; Egger was in the belief, it appears from the publication, that 

 Halydai was a correct spelling and the spelling of the generic name Halydaia was 

 therefore intentional (and cannot be held to be an inadvertent error). 



It is necessary to have it established beyond doubt that Halydaia is the correct 

 spelling of the name of the Tachinid genus, because if not then the name Halidaya 

 in tachinids enters into homonymy with Halidaya Rondani in the Sepsidae, which 

 by unfortunate coincidence was published in the same year (1856) as Halydaia 

 Egger. (It is not evident at present whether Egger's or Rondani's was the earlier 

 of the two works, but as Halydaia Egger is held to be valid under the Code there is 

 no homonymy with Halidaya Rondani and it is irrelevent which name is the prior 

 one.) 



Key to Australian Genera of Thelariini 



1 Antennae inserted at a level far below the eye middle (Text-fig. 36). Head in facial 

 view with the eyes converging ventrally so that the facial region is narrower than 

 the frons. Both sexes with 5 or 6 pairs of strong proclinate orbital setae 

 (Text-fig. 36). Arista pubescent. Eyes so large that they reach the peristome 

 and virtually obliterate the gena (Text-fig. 36). Scutellum without discal setae. 

 Interfrontal area reduced, much narrower than a parafrontal. Fore coxa haired 

 only on apical half of the inner anterior surface. Legs reddish yellow (except 

 sometimes for dark tarsi) ....... HALYDAIA Egger 



Antennae inserted at the level of the eye middle (Text-fig. 35). Head in facial 

 view with the eyes slightly or strongly diverging ventrally so that the facial region 

 is wider than the frons. g without proclinate orbital setae, 9 with two pairs. 

 Arista short plumose. Eyes large but not reaching to the peristome, gena distinct 

 and about as wide as third antennal segment (Text-fig. 35). Scutellum with a 

 pair of semi-recumbent discal setae. Interfontal area wider than parafrontal. 

 Fore coxa haired on whole extent of the inner anterior surface. Legs black 



THELAIRA Robineau-Desvoidy 



Tribe MINTHOINI 



This is an Old World tribe containing a few genera of very slender tachinids 

 with long narrow wings and elongate legs. A few New World forms have been 

 placed in the tribe but it is doubtful whether they correctly belong. A curious 

 feature of the group is the conspicuous flattening of the fore tarsi in the females; 



