38 R. W. CROSSKEY 
tuft of very long strong hairs (most of these greatly exceeding the length of v—m). 
Base of costa with exceedingly long hair (obviously much longer than the normal 
wing fringing) extending from just distad of the basicosta for most of the way 
to Sc, but especially strong immediately beyond the basicosta 
GEROCYPTERA Townsend 
— Lower calypter with only the usual very short marginal fringe. Basal node of 
R,., ; ventrally with only a few small hairs or fine setulae, these not exceeding r—-m 
in length. Base of the costa without such exceptionally produced vestiture 
CYLINDROMYIA Meigen 
Tribe LEUCOSTOMATINI 
The small tribe Leucostomatini occurs mainly in Eurasia and North America, 
but a few species of Lewcostoma are found in the Neotropical Region and in the 
Ethiopian Region (principally in South Africa, but isolated specimens are known 
from Sierra Leone and southern Arabia). In Australia the existence of the tribe 
was known for a long time only from a single specimen collected at Sydney (in 
the ANIC, Canberra collection) and identified by Malloch (1930b) as Leucostoma 
simplex (Fallén) but other specimens of this species (or an extremely closely allied 
one in the same genus) have recently been obtained in New South Wales, confirming 
that Leucostoma occurs naturally in Australia. (The specimen named by Malloch 
as L. simplex was examined during the present work and directly compared with 
Fallén’s type and other European material: it appears to be correctly identified 
as this Holarctic species.) 
Townsend’s (1936, 1938) conception of the tribe included a strangely heterogeneous 
assemblage of forms, and he even included the Australian genera Zita Curran and 
Pygidia Malloch in his Leucostomatini. Whilst admitting that these genera are 
hard to place reliably, it is hard to conceive of them as having any relationship with 
Leucostoma. As now understood the tribe is a very homogeneous group including 
forms that are all superficially very similar to Leucostoma in which the end of the 
female abdomen is forcipate, and in which all the members have hemipterous 
hosts. The genus Leucostoma is easily distinguished from the other genera by the 
long-petiolate wing cell R; (a similarly petiolate R,; occurs in the Mexican genus 
Vanderwulpella Townsend, but the female sex is unknown in this genus and the 
current assignment of Vanderwulpella to the Leucostomatini is probably in error). 
A noteworthy feature found in the Leucostomatini is the great development of 
the lower calyptrae in the males of some forms. In the Oriental genus Calyptromyia 
Villeneuve these are exceptionally large (to which feature the generic name alludes) 
and dull opaque white, and in males of an undescribed leucostomatine from 
Madagascar they are so enormous that they completely conceal the abdomen; in 
this undescribed species the lower calyptrae are (relative to body size) without 
doubt the largest known in the Diptera, and, being brilliant opaque white contrasting 
with the shining black head and thorax, give the fly a most spectacular appearance. 
The chief characteristics of the Leucostomatini are as follows. Head dichoptic but frons 
strongly contracted dorsally in g, eye facets not enlarged; 9 with two pairs of proclinate 
orbital setae (or upper pair divaricate), usually with a pair of outwardly directed prevertical 
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