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 Halidaya, 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 ‘Ich 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 Halydaza 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. @ without proclinate orbital setae, 2 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; 
