44 R. W. CROSSKEY 



propleuron is black haired and in which there is no facial keel, the genera Geraldia, 

 Acucera, Platytainia, Hobartia and Anatropomyia coming in this category; the first 

 three of these genera have the parafacials covered with strong black hair. This 

 complex seems to be uniquely Australian and has no counterpart in the fauna of 

 the Oriental Region, but some members closely resemble certain Neotropical forms: 

 Anatropomyia, for example, has the same essential characters and very closely 

 resembles 'Theresia' erecta Aldrich from southern Chile (the generic name for this 

 species is placed in inverted commas because the species undoubtedly is wrongly 

 placed in Theresia Robineau-Desvoidy but has not yet been reassigned) . 



Two genera here placed in the Prosenini were recently placed by Paramonov 

 (1968) in the Rutiliini, viz. Ola and Ruya (= Rutilotrixa) . These genera (which 

 are so similar to each other that separate generic status is only doubtfully warranted) 

 have a sharp median facial keel (unlike the carina of Rutiliini or of the Prosena 

 group of genera) and an aggregate of characters that better places them in the 

 Prosenini rather than the Rutiliini, though they are to some extent intermediate. 

 The affinities of Ola and Rutilotrixa are uncertain, but they closely resemble some 

 similarly robust Prosenini from the southern Neotropical Region, especially 

 Psecacera Bigot. 



The genus Trichostylum is disjunct from the rest of the Australian Prosenini. 

 Its overall facies leaves no doubt at a glance that it belongs in the Billaea Robineau- 

 Desvoidy complex of genera (or so-called genera) that are a significant component 

 of the prosenine fauna of Africa and Eurasia. The holotype of the type-species 

 has the propleura totally bare (in contrast to the haired propleuron of Billaea 

 s.l., Philotrichostylum Townsend, etc.) and the genus is on this account retained 

 as valid at present, but apart from the bare propleuron it is scarcely distinguishable 

 from certain species of Billaea s.l. that lack a facial carina. 



The genus Heterometopia Macquart is uniquely Australian and may not truly 

 belong in the Prosenini (where it is here placed as an interim measure) until its 

 characters can be more fully studied and its hosts discovered). It is an aberrant 

 genus in respect of its head structure and especially difficult to place at present. 

 If not a prosenine then it ought probably to be placed in the Tachininae either 

 in the tribe Thelairini or in the tribe Leskiini. A study of the male genitalia would 

 probably help in determining its position. 



Key to Australian Genera of PROSENINI 



Head with a large elongate facial carina separating the antennae, the carina 

 convex or flattened on its anterior surface (never forming a sharp ridge) and 

 when seen in profile appearing abruptly marked off from the epistome by a 

 strong concavity (Text-fig. 27). Palpi very reduced, shorter than or at most 

 only as long as the third antennal segment. Two sternopleural setae (except 

 in Prosenina with three). Arista plumose. [Mainly slender forms in which 

 males have exceptionally spindly legs with attenuate, often sinuous, tibiae] 



Head without a facial carina or with a rather sharp roof-like median ridge that 

 does not clearly separate the antennae and when seen in profile is not marked 

 off from the epistome by a definite concavity. Palpi well developed, obviously 



