38 R. W. CROSSKEY 



tuft of very long strong hairs (most of these greatly exceeding the length of r-*w). 

 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 5c, but especially strong immediately beyond the basicosta 



GEROCYPTERA Townsend 

 - Lower calypter with only the usual very short marginal fringe. Basal node of 

 i? 4 , 5 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 Leucostoma 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 (19306) as Leucostoma 

 simplex (Fallen) 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 

 Fallen'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 5 (a similarly petiolate R 5 occurs in the Mexican genus 

 Vanderwuipella Townsend, but the female sex is unknown in this genus and the 

 current assignment of Vanderwuipella 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 $, eye facets not enlarged; $ with two pairs of proclinate 

 orbital setae (or upper pair divaricate), usually with a pair of outwardly directed prevertical 



