16 R. W. CROSSKEY 
lower calypter. The larger ventral one of the pair of membranous lobes at the 
wing base rigidly attached at its base to the suprasquamal ridge (squama, 
thoracic squama, Thorakalschiippchen of Mesnil). 
Taxonomic characters of the lower calypter lie in its shape and vestiture, 
and at specific level in colour. It is well developed in all Tachinidae, and in 
some is grossly enlarged (e.g. in an undescribed Leucostomatine from 
Madagascar the lower calyptrae of the male are so enormous that they completely 
hide the abdomen). In some forms (e.g. Palpostomatini) the lower calypter is 
subcircular posteriorly and diverges from the scutellum but in many it is very 
broad posteriorly and its inner edge abuts close to the scutellum (e.g. Sturmiini 
and many other Goniinae, many Phasiini). In a few Goniinae (Ethillini, some 
Winthemiini, some Carcelia) the outer edge of the lower calypter is bent abruptly 
downwards. Normally the upper surface is bare but fine erect hairing is present 
in a few forms and provides a useful key character (e.g. Nemoraea, some Senostoma, 
some Rutilia (Chrysorutilia)). 
lunula. The crescentic sclerite between the antennal bases and the frons (frontal 
lunule) (Text-fig. 2). 
Useful as a descriptive landmark, but otherwise of little value. Bare in all 
Tachinidae. 
marginal scutellar setae. The strong setae around the edge of the scutellum 
collectively. 
The total number of pairs of these setae can provide a useful key character. 
In a few forms the marginal setae are more numerous than usual, slightly or 
strongly spiniform, and not clearly differentiated into basals, laterals and 
subapicals (e.g. Formosia, Rutilia). 
median marginal setae. Setae standing on the middle part of the hind margin 
of an abdominal tergite (the MM of Townsend). 
mediotergite. The posterodorsal declivity of the thorax below the postscutellum 
and between the halteres (Jateral postscutellar plates + basiscutellum of Townsend) 
(Text-fig. 7). 
Not used in taxonomy except for presence or absence of fine hairs on the 
mediotergite near the base of the lower calypter (infrasquamal hairs, q.v.). 
Shape might have taxonomic value but has been insufficiently investigated. 
In some forms the middle part immediately ventral to the postscutellum (i.e. 
the basiscutellum of Townsend) is differentiated by a distinct line on each side 
from the lateral parts (i.e. the lateral postscutellar plates of Townsend), but in 
others (e.g. Doleschalla) there is little sign of such differentiation. 
mentum. The sclerotized shaft or main plate of the proboscis (figs 12 & 13 in 
Crosskey, 1973). 
Length and shape of the mentum of the proboscis have some taxonomic use, 
e.g. in Rutiliini in which the mentum in some forms seen in profile is distinctly 
tapering while in others it is parallel-sided. 
mesonotum. The prescutum and scutum together (Text-fig. 4). 
Markings of the mesonotum when present, e.g. vittae or spot-patterns, have 
some taxonomic usefulness. Strictly, the mesonotum is formed of a scutum 
