38 RoW. CROSSKE ¥ 
MATERIAL EXAMINED 
Holotype g, InponEs1A: Moluccas, Seram (Ceram), Mansela, 2500 ft, 1919 
(Pratt). In British Museum (Natural History), London. [Genitalia on slide.] 
Paratype. 1 9, INnDoNESIA: Moluccas, Seram (A. R. Wallace) (BMNH, London). 
DISTRIBUTION. Known only from the island of Seram (Ceram) in the Moluccas. 
AFFINITIES. A very distinctive species readily identified at a glance by the 
unicolorous blackish brown colour and large size; no particular affinity with another 
species is evident at present. Although only one male and one female are available 
so far, I have no hesitation in describing the new species because it is so clearly 
distinct from all other known species of the subgenus Euamphibolia, to which fusca 
sp. n. is certainly assignable. 
Genus FORMODEXIA Gen. n. 
Type-species: Rutilia volucelloides Walker, 1861. 
Diacnosis. Facial carina large, with subparallel sides and at most only slightly bulbous 
medially, convex on outer surface. Epistome not very strongly prominent, weakly set off from 
carina by shallow depression. Eyes of very strongly approximated so that upper frons slightly 
narrower than facial carina, the upper facets not noticeably enlarged. Parafacials bare. Buc- 
cal opening very narrow, in ¢ hardly wider than facial carina. Genal dilation moderately 
developed, not reaching forward as far as front level of eye. Head nowhere metallic. Arista 
pubescent. Palpi of both sexes exceptionally long and slender. Proboscis rather long and 
slender and slightly tapering before the labellae. Prosternum and prosternal membrane bare. 
Scutellum with apical pair of setae inserted at lower level than other marginal setae; total of 
six or seven pairs of marginals; disc of scutellum not flattened. Postalar callus with 5 setae. 
Postalar wall with dense hair tuft. Suprasquamal ridge bare. Upper calypter normal. 
Tegula without the usual long wiry posterior setulae. Costal base explanate and with well 
formed close-set curved marginal fringe, wings appearing to have basal ‘shoulder’ to naked eye. 
Abdomen without downwardly-directed spiniform setae on ventral margins of tergites; T3 
without either median or lateral marginal setae; intermediate tergites without discal setae. 
T5 convex, without median depression or prominent posterolateral corners, apical part (behind 
the single transverse setal row) sharply bent downwards in ¢. 
DISTRIBUTION. Only known from the Moluccas, including the islands of Halma- 
hera and Batjan; probably occurring also in other islands of the Moluccas group. 
Discussion. The curious Rutiliine species described by Walker as Rutilia 
volucelloides (of which two other Walker names are synonyms, as indicated later) 
from the Molucca islands has a suite of characters which preclude it from being 
placed satisfactorily in any of the genus-group segregates of Rutiliini already des- 
cribed, and in order to present a balanced classification of this tribe it is necessary 
to assign volucelloides to a new genus, for which the name Formodexia gen. n. is 
proposed. 
Formodexia gen. n. agrees with Formosza, and differs from all other Rutiliine genera, 
by having the postalar wall haired, but it differs from Formosia in having the 
apical scutellar setae set lower than the others, in the explanate costal base and 
lack of wiry posterior hairs on the tegula, and in lacking the strong downward-point- 
ing spinous setae on the abdominal venter which are characteristic of Formosia; 
