10 PROCEEDINGS OF THE NATIONAL MUSEUM vol.66 



becoming longer and Avith three small bristles on lower anterior edge 

 near the tip. Fore and middle tibiae yelloAV, -with short hair and 

 small bristles. Hind tibiae brown with long hair, especially below. 

 Fore and middle tarsi yellow, darkened toward their tips; joints 

 of fore pair as 66-22-18-12-10. Hind tarsi brownish; first joint 

 thickened, especially at base, with two roAvs of long bristles below ; 

 joints of hind tarsi as 105-40-30-19-18. Calypters and halteres 

 3'ellow, the former with their tips slightly brown and their cilia 

 black. 



Wings dark grayish ; third vein bent backward at tip ; last section 

 of fourth vein bent before its middle, parallel Avith third beyond the 

 bend ; last section of fifth vein nearly tAvice as long as the crossvein. 



Described from tAvo males taken by Dr. J. M. Aldrich, at Mono 

 Lake, California, July 22, 1911. 



This is the fourth species to be described from America that has 

 the first joint of hind tarsi much longer than the second and fur- 

 nished Avith long bristles. 



Type.—M^lQ, Cat. Xo. 27040, U.S.N.M. 



10. ARGYRA FEMORALIS, new species 



Male. — Length, 3.5 mm. Face, front, palpi, and proboscis black; 

 still in certain lights they shoAV a little broAvnish-gray pollen; face 

 rather wide for a male. Antennae black, first joint Avith conspicu- 

 ous hairs aboA^e; third joint about as long as the basal tAvo taken 

 together, obtusely pointed; arista inserted just aboA^e the point, 

 scarcely as long as the antenna. Lower orbital cilia grayish; the 

 small, black, upper cilia reach doAvn about one-fourth the eye 

 height. 



Dorsum of the thorax dark, shining green, its silveiy pollen con- 

 fined to a band extending from beloAV the humeri to, and a little 

 aboA'e, the root of the wing; scutellum Avith tAvo pairs of marginal 

 bristles, the outer pair about half as large as the median ones. 

 Abdomen metallic green Avith the third and folloAving segments 

 covered Avith abundant silvery pollen, its hairs and bristles wholly 

 black. Hypopygium small, black; outer lamellae small, black, ob- 

 tuse at tip and fringed Avith hairs; inner appendages are a pair of 

 yellow^, slightly clubbed, short organs, Avith tAvo or three short 

 hairs at tip. 



Coxae black with black hairs and bristles, fore coxae yelloAv at 

 tip and with a roAv of slender bristles on apical half of outer anterior 

 edge, Avhich are longest above, Avhere they are as long as the thickness 

 of the coxa. All femora and tarsi black, extreme tips of femora 

 yellow; anterior femora Avith long, black hair on the posterior sur- 

 face; middle pair (fig. 12) with a protuberance beloAv, where there 

 are a few dose-set, short spines; hind femora Avith long, black hair 



