40 RW. CROSSIKE ¥ 
INCLUDED SPECIES 
Formodexia volucelloides (Walker) comb. n. Motuccas. [Lectotype exa- 
mined]. 
trixoides (Walker) syn. n. [Holotype examined]. 
ignobilis (Walker) syn. n. [Holotype examined]. 
Genus RUTILODEXIA Townsend 
Rutilodexia Townsend, 1915 : 23. Type-species: Rutilia angustipennis Walker, 1859, by original 
designation. 
Bothrostiva Enderlein, 1936 : 413. Type-species: Bothrostiva prisca Enderlein, 1936, by original 
designation. Syn. n. 
Rutilosia Paramonov, 1968 : 355. [Name published in footnote to generic key: unavailable 
under Article 13 (b) of International Code of Zoological Nomenclature, no fixation of type- 
species. ] 
Diacnosis. Facial carina large and subparallel-sided, at most slightly widened medially, 
often slightly sulcate. Epistome not strongly prominent, separated from facial carina by very 
shallow depression only. Eyes of § not very strongly approximated, upper frons at least as 
wide as and usually a little wider than facial carina, upper facets not enlarged. Parafacials 
bare. Buccal opening wide, very much wider than facial carina in both sexes. Genal dilation 
weakly developed, anterior edge very remote from epistome. Head nowhere metallic. 
Arista pubescent. Palpi fully developed normal size. Proboscis short, rather slender and 
tapering before labellae. Prosternum and prosternal membrane bare. Scutellum with apical 
pair of setae inserted at lower level than other marginal setae (apicals sometimes hair-like) ; 
total of 7-11 pairs of marginals; disc of scutellum not noticeably flattened. Postalar callus 
with 4-6 setae. Postalar wall bare (at most a very few hairs adjacent to those on callus edge). 
Suprasquamal ridge bare. Upper calypter normal. Tegula with normal long wiry posterior 
setula. Costal base not explanate. Abdomen with slightly spiniform setae ventrally on tergite 
margins which are directed downwards and backwards; T3 without median marginal setae in g, 
with single pair of such setae in 2; intermediate tergites without discal setae. T5 broad, without 
or with at most only slight median depression, posterior corners not prominent. 
DISTRIBUTION. Aru Islands, New Guinea and New Britain. 
Discussion. It is considered best to recognize Rutilodexia Townsend as a valid 
genus for a small group of species found (so far) only in the Papuan subregion and 
differing on total suite of characters from the species placed in Rutilia s.1., though 
undoubtedly Rutilodexia is very closely allied to Rutilia and does not differ from it 
by very convincing characters. The general appearance of Rutilodexia species is 
very similar to some Rutilia (especially in the subgenus Donovanius Enderlein), and 
Rutilodexia has the bare postalar wall and low-set apical scutellar setae exactly as in 
Rutilia; furthermore, the facial carina is exactly of the Rutilia type. The supra- 
squamal ridge is, however, bare in Rutilodexia and this character provides a distinc- 
tion from almost all of Rutilia species; in Rutilia the suprasquamal ridge is nearly 
always haired, but there are some species which (on overall balance of characters) 
must be placed in Rutilia even though the ridge is bare. The best feature for 
distinguishing all Rutilodexia from all Rwutilia seems to lie in the genal dilation 
(Text-figs 4 & 5); in Rutilodexia this is unusually small and its anterior limit is formed 
by an oblique ridge extending downwards from behind the eye; in Rutilia the genal 






