332 BULLETIN UNITED STATES GEOLOGICAL SURVEY. 



wliitisli-pruinose alonoj the eyes ; face whitish-pruiuose, its ground-color 

 variable, dark metallic-greeu, with more or less brownish-yellow on the 

 sides and on the facial tubercle, or entirely yellowish ; antennae brown 

 or reddish brown, inserted on brownish-yellow ground. Thorax metal- 

 lic greenish-black, with vestiges of whitish-pruinose stripes anteriorly; 

 pleurse whitish-pruinose, with white pile ; scutellum translucent yellow- 

 ish-brown, with a metallic reflection ; halteres with yellow knobs. Ab- 

 domen black, shining, with bronze and bluish reflections; a broad 

 blood-red cross-band slightly emarginate in the middle posteriorly, at the 

 base of the third and fourth segments; these cross-bauds are slightly 

 pruinose ; the sides of the abdomen beset with white pile. Legs pale 

 yellow ; hind femora and tibite usually each with a brownish ring; some- 

 times the leg's are more brownish, especially on the femora. Wings hy- 

 aline: the root before the humeral cross- vein and the extreme base of 

 the second basal cell is infuscated ; costal cell hyaline, but the interval 

 between auxiliary and first veins is pale brownish ; stigma dark brown 

 the corner between the costa and the end of the first vein yellowish ; a 

 brown, incomplete cross-band between the first and fifth veins; it coa- 

 lesces with the brown stigma, leaves hyaline the extreme proximal end 

 of the submarginal cell, covers the small cross- vein and the cross-vein 

 at the l)ase of the discal cell, bat reaches only very little beyond' either, 

 and ends at the fifth vein, filling up the proximal end of the fourth pos- 

 terior cell. 



Hab. — Santa Monica, Cal., February 18; Summit Station, Sierra Ne- 

 vada, July 17; Fort Bridger, Wyo., August 4; Morino Valley, jS"ew 

 Mexico, July 1, W. L. Carpenter. One male and three females. 



Baccha angusta n. sp. — Wings hyaline at the base, slightly shaded 

 with brownish-gray beyond the cross-veins; abdomen with two yellow 

 cross-bands. Length 7-8™"". 



Male. — Face and front metallic green ; antennae brownish (the hedd is 

 somewhat injured in my specimen.) Thorax and scutellum bronze-color; 

 halteres brownish yellow ; the tip of the knob brownish. Abdomen : 

 two first segments bronze-color, the second long and very slender, the 

 remainder metallic-brown, with brownish-yellow cross-bands at the 

 base of the third and fourth segments; the cross-band on the fourth 

 segment occupies about one-third of its breadth ; that on the third is a 

 little narrower. Wings hyaline from the root to the central cross- veins, 

 slightly tinged with grayish beyond : a brown cloud between the tip Of 

 the auxiliary vein and the first vein ; beyond this cloud, the space be- 

 tween the costa and the first vein is brownish-yellow. Legs yellowish 

 more or less tinged with brown in the hind pair. 



Rob. — Lagunitas Creek, Marin County, California, April 15. A sin- 

 gle male. 



YoLUCELLA MExrcANA Macquart. — Besides Mexico and Texas, this 

 species occurs in Southern California. I have received specimens from 



