REVISIONARY CLASSIFICATION OF RUTILIINI 2 
place into a subtribe or tribe with any confidence. Considering the whole of the 
Proseninae there is no doubt that the great bulk of forms constitute one very large 
tribe (Prosenini) containing much variety of form but united by all perceptible shades 
of intermediate characters, but that there are some other large groups or small 
groups that are more disjunct from the main body of forms and which can justifiably 
be ranked as tribes equivalent to the Prosenini; these include the Rutiliini, Doleschal- 
lini and Trixini, and perhaps a few other definable tribes when sufficiently studied. 
The Theresiini, Dexillini and Zeliini which Townsend (Manual of Myiology) treated 
as distinct tribes appear to me to be indistinguishable from Prosenini, and I am also 
doubtful whether the Trichodurini can be separated from the Prosenini either. 
The position of the subtribe Stominina of Mesnil (1939 : 52-53) is also very doubtful, 
but in my view it has scarcely any of the characters of the Rutiliini and cannot be 
placed in the Rutiliines where Mesnil has classified it: the characters of Stomina 
Robineau-Desvoidy appear to place this genus close to Billaea Robineau-Desvoidy 
in the Prosenini. At present the various tribal segregates within the Proseninae are 
insufficiently clarified, but the diagnosis here given should certainly distinguish the 
Rutiliini satisfactorily from all other Proseninae (except perhaps for the anomalous 
genus Chetogaster), and the key given in a foregoing section will separate the tribe 
from other tribes of Proseninae found in the Oriento—Australasian regions. 
Although the Rutiliines have been so widely accepted as a family-group segregate, 
and are here ranked as a tribe on their own, it is impossible to characterize them 
as a whole by any simple character or small group of characters in a way that 
absolutely defines them. The best diagnostic feature (though it does not hold for 
| the genus Chetogaster) is the presence of supernumerary strong bristles on the postalar 
callus ; in all other Proseninae (and virtually all Tachinidae) there are only two strong 
setae on the postalar callus, sometimes accompanied by a long hair, but ia all 
Rutiliini (excepting Chetogaster) there are at least three very strong postalar setae 
and sometimes from four to six. Another important character is the snout-like 
| development of the epistome, which projects far in front of the vibrissae in profile 
| (as mentioned by Mesnil, 1939), but some Formosia and Rutilodexia have the epistome 
| only very slightly projecting, and resemble many Prosenines in this respect, so that 
this character, too, is not completely satisfactory. Many Rutiliini have the supra- 
squamal ridge thickly haired and others have a tuft of long hair standing on the 
wall of the postalar callus, and these features are never found in other Proseninae. 
The facial carina is always very strong in Rutiliini, and often very wide and flattened 
(then assuming a form almost never found among other Prosenines), and many 
members of the tribe have very strong erect spiniform setae on the abdomen or long 
| strong spiniform setae on the scutellum and mid and hind coxae; such spiniform 
setae are of rare occurrence in other Proseninae, although they are found in several 
South American genera and in the Nearctic genus Euchaetogyne Townsend, but the 
New World forms which slightly resemble Australasian Rutiliini can always be 
easily distinguished by possessing only the two normal setae on the postalar callus 
and usually by having the propleuron bare (though in Euchaetogyne the propleuron 
is haired, asin the Rutiliini). The males of all Rutiliini have some very characteristic 
long strong bristles on tergite 7 + 8 of the hypopygium, these bristles standing in 



