68 R. W. CROSSKEY 
pairs of strong setae, the bend of vein M lacks an appendage, cell R; is open to 
the wing margin or only just closed, and there are two or three stf/ setae. Some 
forms occur, less typical of their tribe, that have hairy eyes, four post dc setae, 
infrasquamal hairs, and three pairs of scutellar setae. Pallid coloration and reddish 
yellow legs are rather commonly found in the group, and there is a tendency for 
the tibiae of the males of the really long-legged forms to become extremely slender 
and sinuous with associated reduction of the bristling (here it should be noted that 
the mid tibia in Leskiini appears always to possess a submedian v seta but that this 
is often extemely small in long-legged males). 
The endemic genus Exechopalpus possesses extraordinarily long palpi, similar to 
those of the Neotropical genus Spathipalpus Rondani, and the proboscis itself is 
extremely slender. Throughout the Leskini there is a marked tendency for the 
proboscis to be unusually slender, elongate, almost stylet-like, with the labellae 
correspondingly reduced, and even in forms in which the proboscis is short it is 
usually found that the mentum is parallel-sided in profile rather than convex 
on its lower edge. 
The genus Bezziomyiobia Baranov from the Solomon Islands has not been 
found in Australia, but is included in the following key to genera to show its main 
features. It is extremely close to Demoticoides Mesnil, and the latter ought perhaps 
to be sunk as a synonym of Bezziomyiobia (it is beyond the scope of the present work 
to consider this further). 
KerEy To AUSTRALIAN GENERA OF LESKIINI 
1 Scutellum with only two pairs of strong marginal setae, the basals and subapicals; 
apical scutellar setae minute and hair-like or absent, if weakly developed then 
directed half-upwards. Subapical scutellar setae not inserted very widely apart, 
distance between their bases subequal to or less than that between a subapical 
seta and its corresponding basal seta : 2 
— Scutellum with three pairs of strong marginal = a oak of strong horizaatel 
crossed apical setae present in addition to the basals and subapicals. Subapical 
scutellar setae inserted very widely apart, distance between their bases about twice 
as great as that between a subapical seta and its corresponding basal seta (or even 
more than this) . 8 
2 Palpi exceptionally Sunes length sleet eaeal to that of ead at level a the 
epistome; palpi projecting beyond epistome by a distance about equal to the 
antennal length (when proboscis retracted). Fore tibia with some strong ad 
setae. Mid tibia with three or four strong ad setae and with three strong p 
setae. Hind tibia with a pu apical seta . : . EXECHOPALPUS Macquart 
— Palpi normal, length conspicuously less than that of head at level of the epistome; 
palpi not or only a little projecting beyond epistome (when proboscis retracted) 
(Text-fig. 41). Fore tibia without ad setae (a few inconspicuous ad setulae on 
basal half in Rhinomyobia). Mid tibia with one or two ad setae and nearly 
always with two p setae (some Towxocnemis-like forms with a very small third p 
seta basad of the normal two). Hind tibia without a pu apical seta (except in 
Sipholeskia) . : : : : : : 3 
3 Abdomen with Ti + 2 ae to Be pad eee Second costal sector bare 
ventrally. Humeral callus with three or more setae in line (sometimes not 
clearly differentiated from long hair). More robust forms with subovate or 
subconical abdomen } : ; : E : : : 3 : : 4 
