THE CANADIAN ENTOMOLOGIST 153 



thorax unmarked with darker; male hypopygium with the median lobe of the 

 ninth tergite short, the caudal margin with a broad, U-shapcd notch. 



Male. — Length 22 mm.; wing 21.5 mm. Hind leg, femur 12.1 mm.; tibia 

 14.6 mm. 



Female. — Length 2() mm.; wing 18. o mm. 



Head and frontal prolongation clear light >ellow; rostrum and palpi pale 

 brown. Antennse with the scape yellow; flagellum light brown, the basal swell- 

 ings indistinctly paler, brownish yellow. 



Mesonotum orange-\ellow, the pra^scutum and scutum with the usual three 

 stripes lacking or barely indicated; scutellum and postnotum clearer yellow, 

 unmarked. Pleura clear orange-yellow, unmarked. Halteres light brown, 

 the base of tiie stem narrowly light yellow\ Legs with the coxae and trochanters 

 orange-yellow; femora yellowish brown, the tips broadly blackened; tibia? light 

 brown, the tips scarcely darkened; tarsi brown; claws toothed. Wings brownish 

 subhyaline, cell C more yellowish, cell Sc more brownish; stigma brown; very 

 indistinct seams along r-m and the basal deflection of Ciiu' veins dark brown. 

 Wnation: as in the subgenus; fusion of Mz and Cui punctiform. 



Abdomen with the basal tergites orange-yellow, the basal third of the in- 

 termediate segments paler yellow and destitute of pubescence; segments six to 

 nine more yellowish brown; a conspicuous, interrupted, brown, lateral stripe 

 on tergites two to four. In the female, the dark lateral stripe is more extensive. 

 Male hypopygium as in thezambeci en si sgroupbut rather more enlarged than usual. 

 Ninth tergite with the median lobe short, the caudal margin with a broad and 

 deep U-shaped notch, the lateral lobes rather slender, lying subparallel ; viewed 

 from the side, appearing as conspicuous flattened blades. Outer pleural ap- 

 pendage pale yellow, elongate-oval, the apex obtusely rounded, the outer face 

 of the lobe with sparse bristles, longer and fringe-like at the apex. Inner pleural 

 appendage moderately complicated in structure, consisting of an inner blade 

 that juts against the ninth tergite, the proximal face densely clothed with long, 

 yellow hairs, and an outer blade that bears a somewhat oval area of about a 

 score of erect, black, spinous bristles; between these two blades lies a slightly 

 curved, cylindrical arm with the apex truncated and heavily chitinized. Ninth 

 sterno-pleurite with a broad and very deep \'-shaped median notch that is 

 deeper than in any other species of this group so far made known, the base 

 lying underneath the caudal margin of the eighth sternite; beneath this profound 

 incision is a membranous tissue, at about mid-length of the split with two 

 contiguous flattened lobes', each fringed with a sheath of reddish bristles that 

 are directed caudad, these longest proximally, decreasing in length outwardly. 

 Ovipositor with the tergal valves very slender, straight; sternal valves com- 

 pressed, the tips obtuse. 



Habitat. — Madagascar. 



Holot.ype.— d'. (W. D. Cowan). B.M. No. 80-45. 



Allotype. — 9, Region south-east of Fort Dauphin, December, 1900, (Ch. 

 Alluaud). 



Paratopotype. — (^ . 



Paraiypes. — cf, Ambohimitombo Forest, November, 1894. CDr. Forsyth- 

 Major); c^, Tamatave. 1906, (A. .Sauzier). B.M. Nos. 98-46, 1906-291; 6 

 & 9 's, Foret e d'Andrangoloaka, Imerina. 1891, (A. Grandidier). 



