PROCEEDINGS OF THE NATIONAL MUSEUM vol. GG 



23. Fourtb, fifth, and mo.st of third abdominal segments blaclv or green. 



28. minuta Loew. 



Abdomen yellow with the last segment and narrow hind margins of the 



others black or green 24 



24. Palpi black or brown 29, flavipes, new species. 



Palpi yellow 26, setipes, new species. 



25. Abdomen black with yellow .spots on the sides of second, third, and some- 



times the fourth segments 11, albiventris Loew. 



Abdomen yellow with the last segment and narrow hind margins of the 

 others black or green 26, setipes, new species. 



B. Suhgenus Leucostola — 3Iales 



1. Hind femora black or brown at tip, at least above 2 



Hind femora wholly yellow 4 



2. Hind tibiae and tarsi almost wholly blackish 34, involuta, new species. 



Hind tibiae wholly yellow 3 



3. Hind tarsus with its joints in the proportion of 23-17-12-8-6 (Indiana). 



36, inaequalis, new species. 

 Hind tarsus with its joints as 24-23-16-9-7 (Indiana). 



37, spina, new species. 



4. Hairs of fore coxae yellow, their bristles black (Florida). 



35, flavicoxa, new species. 

 Hairs and bristles of fore coxae wholly yellow 5 



5. Tip of hind basitarsus slightly enlarged and with close-set little hairs 



which make it appear even larger (District of Columbia; Virginia; New 



York; New Jersey; Indiana; Louisiana) 32, cingulata Loew. 



Hind basitarsus not at all enlarged at tip, but with a row of equally .spaced, 

 stiff, little hairs below, which are continued on the following joints (New 

 Jersey; Pennsylvania) 33, johnsoni, new species. 



1. ARGYRA NIGRIPES Loew 



« 



Argyra nigripes Loew, Smiths. Misc. Coll., No. 171, p. 127, 1864. 



Male. — Length, 3.5-4.5 mm. Front and face velvety black, the 

 latter moderately narroAv. Proboscis and palpi black, with black 

 hairs. Antennae black: first joint with conspicuous hairs above; 

 third joint about as long as the first, roimded at tip; arista inserted 

 before the tip, as long as the antenna. Lower orbital cilia vary in 

 color from brownish gray to grayish white : the minute black upper 

 orbital cilia reach to about the middle of the eye height. 



Dorsum of thorax shining green with coppery reflections, its sil- 

 very pollen confined to the sides ; sometimes the scutellum and poste- 

 rior part of the thorax are a beautiful blue color; scutellum with 

 two pair of marginal bristles, the outer about half as long as the 

 median pair; pleurae black, with white pollen. Abdomen black, 

 with two first segments more or less green, thickly covered with sil- 

 very white pollen ; its hairs and bristles rather long, wholly Ijlack. 

 H.vpopygium (fig. 1) and its appendages black, penis yellow; the 

 outer lamellae are broad, obtusely pointed at tip, fringed with long 

 black hairs. 



