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or about xanthine or Mars orange (Ridgway), forming a narrow, more 

 or less arcuate transverse band on the anterior part ; in paler specimens 

 the band is wider or reaching practically to the anterior margin of the 

 scutum, and the axillae and scutellum are entirely orange yellow ; propo- 

 deum concolorous, somewhat dusky with a bright luster ; abdomen 

 shining blue black above with a strong luster, and with a greenish luster 

 beneath. Antennae dark brown to black, the scape pale yellowish or 

 whitisli with its dorsal margin and the lower margin of the radicle joint 

 black. Front and hind coxae, most of the front and middle femora and 

 of the hind tarsi white or yelowish white; dorsal and ventral margins of 

 the front femora, their tibiae and tarsi fuscous; middle coxae, upper 

 side of middle femora and base of their tibiae blackish, the tibiae chang- 

 ing to brownish yellow at apex with the spur and tarsi concolorous ; 

 hind femora brownish yellow becoming blackish on the dorsal margin or 

 almost entirely blackish, the hind tibiae and basal half or sometimes only 

 the basal fourth or fifth of the first joint of their tarsi black; apex of 

 the middle and hind tarsi blackish. Wings deeply infuscated with the 

 usual hyaline area beyond the 'transverse fascicle of hair, the hind wings 

 entirely hyaline ; the veins fuscous, but the apical part of the submarginal 

 vein hyaline, coterminous with the hyaline area of the disk. 



Male : Quite dissimilar from the female in many respects. The 

 head much thinner fronto-occipitally, with the eyes much smaller ; carinae 

 of the face, cheeks, and vertex entirely absent ; frontovertex about twice 

 as wide as long with the ocelli arranged in an extremely obtuse triangle, 

 the median ocellus being hardly more than twice as far from the occipi- 

 tal margin as the posterior pair which are rather remote from the eyes. 

 Antennae inserted higher up on the face ; the scape short, flattened and 

 widened towards apex ; pedicel short or no longer than thick ; flagellum 

 cylindrical and slightly thicker than the pedicel; funicle joints nearly 

 equal in length, about twice as long as thick, incised at the articulations 

 and each with two whorls of long hair ; club solid, nearly as long as the 

 two preceding joints combined, tapering towards the acute apex, and 

 clothed with long hair which gradually shortens towards the apex. 



Thorax nearly as in the female, but the axillae much less elevated and 

 not so strongly or abruptly declivous posteriorly ; abdomen a little shorter 

 than the thorax, strongly depressed, subtriangular with the sides equal 

 and the basal corners and apex rounded. Wings without the transverse 

 band of hairs on the basal half, the disk uniformly ciliated ; the speculum 

 widening towards the posterior margin and interrupted below the middle ; 

 marginal vein slightly longer than in the female, the postmarginal pro- 

 portionately much longer, the stigmal, although by no means ^hort, is 

 relatively somewhat shorter than in the female, and hardly longer than 

 half the postmarginal. 



Sculpture as in the female, except that the head is granular alutaceous 

 and opaque like the thorax. Pubescence on the face and frontovertex 

 similar, but the black beard on the cheeks, clypeus and mandibles entirely 

 absent ; mesoscutum and axillae with short, recumbent black hair, the 



