TACHINIDAE OF AUSTRALIA 71 
2 Upper half of face raised medially into a definite ridge-like or knob-like keel beneath 
the antennae, the keel easily visible when head seen in profile. Abdomen with 
dense white pollinosity on each side of the last visible tergite (T5), this tergite 
therefore contrasting in appearance with shining remainder of abdomen. Thoracic 
dorsum not shining . : : MACROCHLORIA Malloch 
— Upper half of face slightly swollen medially but not raised into a keel, face therefore 
almost completely invisible in profile. Abdomen entirely shining, if some 
whitish pollinosity present then rather evenly distributed and very inconspicuous. 
Thoracic dorsum distinctly shining . . CHLOROTACHINA Townsend 
3 Parafacials bare. Propleuron bare. Wing mth cell R; open at the wing margin. 
Form with remarkable pattern, as follows: dorsum ee thorax very pale greyish 
yellow with six large strongly contrasting black marks (sublateral pair on prescutum 
and a lateral and a sublateral pair on scutum); abdominal dorsum black on 
Tr + 2 and T3 (except for pair of pale greyish yellow marks anteriorly on outer 
edges of T3) and densely covered with pale greyish yellow pollinosity on T4 and 
T5, T4 with three bold black spots (median spot and a pair of lateral spots that 
continue round to ventral surface). Apical half of wing irregularly smoky 
brownish, the brown colour nowhere sharply contrasting with hyaline areas 
AMPHITROPESA Townsend 
— Parafacials haired (Text-fig. 45). Propleuron haired. Wing with cell R; closed at or 
a little before the margin. Without such pattern, but marked as follows: dorsum 
of thorax with shining black prescutum and scutum contrasting with yellow or 
orange scutellum, humeral calli and notopleura, the pale areas with pale golden 
pollinosity; abdomen bright orange with a broad black fascia across the middle 
covering T4 and apical part of T3, usually also three small black spots on T5 and 
median depression of Tr + 2 dark. Wing with a sharply defined but irregular 
brown cross-band, and with the membrane clear hyaline distally to the cross-band 
NEXIMYIA Crosskey 
Tribe PARERIGONINI 
This rare and aberrant group, first defined by Mesnil (1966 : 888), occurs in 
Eurasia, New Guinea and Australia. Its relationships with other tribes are at present 
very obscure, but the unusual modification of the male postabdomen, the unusual 
male genitalia, and the variously modified female terminalia, should shed some 
light on the true affinities when they are studied in detail. Superficially the New 
Guinea forms much resemble some Goniinae, and Australian forms like Zita have 
a general appearance, head facies and scutellar bristling much like some Proseninae; 
there is also some superficial resemblance to the Linnaemyini, mainly because of 
the prominent epistome and high vibrissae, and Pygidimyia has the colour and 
form much as in Chaetophthalmus. The Australian genera are known only from 
very few specimens, but these include representatives of some new species. 
The main characteristics shown by the Australian Parerigonini are as follows. Epistome 
prominent and vibrissae inserted high above the epistomal margin; parafacials bare; genal 
dilation well developed; g without proclinate orbital setae, 2 with a pair of outwardly directed 
prevertical setae; inner vertical setae often convergent or crossing; upper occiput without 
black setulae behind the postocular row; prosternum bare; propleuron usually haired; humeral 
callus with three strong setae in a triangle, and one smaller seta set forwards of the inner two 
of the triangle; 3 (4) + 3 dc setae; 0 + 2 ia setae (the two post ia setae very strong and 
normally inserted in a position that suggests that a third post ia is never developed); three 
