TACHINIDAE OF AUSTRALIA 43 
haired along its length (except in Chetogastey in which hind part bare). Head 
always with a strong facial carina. Scutellum with four or more pairs of marginal 
setae (except in Chetogaster with three). Male hypopygium with long strong 
erect setae on T7 + 8 (usually standing in line on each side of the tergite). 
Prosternal membrane bare or haired, prosternum bare except in some forms with 
haired prosternal membrane . : : c : 6 : RUTILIINI (p. 47) 
Tribe PROSENINI 
This tribe contains the great bulk of members of the subfamily Proseninae when 
the whole world fauna is considered, but in Australia (even allowing that there 
are doubtless many undescribed forms) forms only a minor proportion of the total 
prosenine fauna — most of the Australian fauna being comprised by the Rutiliini. 
The features that differentiate the Prosenini from the Rutiliini are shown in the 
foregoing key to tribes, and the characteristics of the Prosenini need not be detailed 
here (further information is, however, given in Crosskey, 1973). The Australian 
Prosenini fall into two main groups, one containing forms with a heavy broad 
facial carina that fully separates the antennae and with reduced palpi, and another 
group (somewhat diverse in its components) containing forms without a facial 
carina, or with a sharp median facial ridge, and with fully developed palpi. 
The first of these groups contains the widespread Old World genus Prosena 
in which the proboscis is enormously elongate and slender, and a complex of forms 
closely related to Prosena in which the proboscis is much shorter and stiffer. Several 
genera have been proposed among the latter forms (Senostoma, Rhynchiodexia, 
Austrodexia, Macropodexia, Lasiocalypter, Lasiocalytrina) but these merge so 
imperceptibly into one another — with few character breaks that are maintained 
when sufficient material is examined of the complex—that it is impossible to 
recognize most of them as valid genera. The oldest name applying to the complex 
of forms with short proboscis, strong facial carina, and reduced palpi is Senostoma 
Macquart (a name misused for many years and erroneously applied to various 
rutiliines) and all the other names, except Macropodexia, are here placed as synonyms 
of Senostoma; the broad genus so recognized can be identified by the accompanying 
key to genera. The genus Macropodexia is superficially hardly distinguishable 
from many of the species of Senostoma, but it has the propleuron thickly pale 
haired and so differs from all Senostoma s.1. and from Prosena; probably Macropodexia 
ought also to be placed as a synonym of Senostoma and the definition of the genus 
widened, but it is here preferred to retain Macropodexia as valid until the whole 
complex can be studied in more detail by an Australian worker with more material 
to hand. It is of interest to note that the propleural hair is white in Macropodexia 
whereas it is black in all other known Australian Prosenini with haired propleuron. 
The second group contains a number of endemic Australian genera that differ 
from the first group (Prosena, Senostoma complex) in having fully developed palpi 
and in the conformation of the facial region of the head (either lacking a facial 
carina or having a sharp ridge-like keel). The forms in this second group are rather 
diversified. Most of them form an apparently natural complex in which the 
