28 R. W. CROSSKEY 
Tue VIRIDIVENTRIS-GRovupP 
Diacnosis. Facial carina unusually narrow, in facial view subequal in width to an antenna. 
Head entirely pollinose, no bare metallic areas. Thorax and abdomen unicolorous dark green, 
no pattern. Abdominal T5 with some long strong setae laterally behind the transverse row 
of setae. Surstylus of ¢ genitalia sharply pointed (Text-fig. 49). 
INCLUDED SPECIES 
Formosia (Formosia) viridiventris Crosskey sp. nm. GUADALCANAL. [Des- 
cribed below]. 
Formosia (Formosia) viridiventris sp. n. 
(Text-fig. 49) 
6. Head. Ground colour blackish, except upper part of facial carina and lunula more 
reddish brown, interfrontal area velvety black-brown; head rather thickly yellowish white 
pollinose, nowhere metallic but trace of greenish colour showing through pollinosity along 
lines of postocular setulae. Parafrontal and genal hair blackish, occipital hair yellowish white. 
Eyes strongly approximated but head not holoptic, upper facets not enlarged, upper part of 
interfrontal area almost eliminated by coming together of parafrontals in mid line; frons at 
narrowest point 0-06—-0:075 of head width, subequal to width of facial carina. Ocelli slightly 
raised, ocellar setae weak hair-like. Facial carina long, very slightly fusiform, longer than the 
epistome, facial profile only very slightly and evenly concave at junction of epistome and carina. 
Gena broad, 0-33—0-38 of eye-height. Parafacial about twice as wide as third antennal segment. 
Antennae dark reddish brown to blackish brown, more orange at junction of second and third 
segments, falling short of mouth-margin by about length of third segment; third segment 
2°6-3-0 times as long as second segment; arista very short plumose. Palpi dark brown or dark 
reddish brown with slightly paler tips. Mentum tapering, rather slender. Thovav. Uni- 
colorous very dark green or bluish green metallic, sometimes with violaceous tinges. Prescutum 
in some lights showing trace of four narrow blackish vittae and thin covering of whitish 
pollinosity, but these so inconspicuous that prescutum appears concolorous metallic greenish 
with the scutum. Thoracic hair all black except for postalar tuft pale yellow and the sparse 
hairing of the propleura yellowish white. Chaetotaxy normal, setae not markedly spiniform. 
Scutellum not flattened; with four pairs of strong marginal setae, these usually immediately 
preceded by some moderately strong horizontal preapical setae. Wings. Basicosta dark 
yellowish brown or reddish brown darkened to blackish brown anteriorly. Wing membrane 
pale smoky brownish with darker brown infuscation along the veins; infuscation conspicuous to 
naked eye and appearing more yellowish brown basally. Calyptrae dark brown with brown 
marginal hair. Legs. Black with entirely black hair; rather elongate and slender with femora 
attenuate on apical halves. Fore coxa fully haired anteriorly; mid femur without or with one a 
submedian seta; hind tibia with one strong ad seta, without ad fringe and without pd setae. 
Claws very long. Abdomen. Dorsum concolorous with thorax, uniformly metallic dark green 
or dark bluish green, venter violaceous towards the sides. Abdominal hairing entirely black; 
hair short, fine, and recumbent. Six setae in the transverse marginal row of T3. T5 with some 
long strong setae standing among the hair on each side behind the setae of the main transverse 
row. Depression of T5 deep and conspicuous. T7 + 8 of hypopygium with only one or two 
long fine setae on each side, and these not very clearly differentiated from the hair vestiture. 
Genitalia (Text-fig. 49) with apical part of surstylus very strongly contracted, curved forwards 
and sharply pointed at tip (somewhat hook-like when seen in profile). Measurements. Body 
length 16-7-18-3 mm (mean 17:5 mm), wing length 14-7-16-5 mm (mean 15-6 mm) [4 specimens, 
holotype with minimum lengths indicated]. 
2. Extremely similar to g except for usual sexual differences. Interfrontal area very dark 
reddish brown, narrowing dorsally but width at minimum about twice as great as a parafrontal; 

