158 BULLETIN 31, UNITED STATES NATIONAL MUSEUM. 



hind femora arc thickened, and both the femora and the tibiae are bent. 

 Wings with a brownish spot ; the third longitudinal vein considerably 

 bent. Type of genus A. bomhiformis, Europe. 



Arctophila flagrans. (Plate VII, figs. 5, ba, 56.) 



Arclophila flagrans Osten Sackeu, Bnll. BufF. Soc. Nat. Sci., iii, 69; West. Dipt., 

 335. 



Habitat— Colorndo (O. S.), New Mexico! 



3 . Length, 13'"'". Face wax yellow. Cheeks black. Antennse : ba- 

 sal joint brownish ; third joint reddish, the plumose arista black. Tho- 

 racic dorsum densely clothed with yellowish hair, through which, how- 

 ever, the metallic, brownish, coppery, ground-color is apparent; pleurae 

 black, in the middle with a stripe formed by yellow pile. Abdomen 

 with long yellow pile at the base and on the sides, with reddish hair in 

 the middle and at the tip ; between the hairs the black metallescent 

 groundcolor is apparent. Legs black ; front tibisB beset on the inside 

 with short golden yellow hairs ; three basal joints of the four posterior 

 tarsi brownish-red. Wings with a slight grayish tiuge; a brown spot 

 limited by the fourth longitudinal vein, the costa, the small cross- vein, 

 and the origin of the third vein ; the latter vein is more deeply sinuate 

 than in A. bombi/orniis. — Osten Sacken, I. c. 



Seven male specimens from New Mexico (G. F. Gaumer, E. Keen) are 

 suflSciently well described by the above. The species is easily recog- 

 nizable. 



ERISTALIS.* 



Eristalis Latreille, Hist. Nat. detj Crust, et Ins., xiv, 363, 1804. 

 Eristalinus Rondani, Dipt. Ital. Prodr., ii, 40, 1857. 

 Erislalomyia Roudani, ibid. 



Moderate sized to large species, often more or less thickly pilose, fre- 

 quently nearly bare, of a prevailing black or brownish-black color, usually 

 with moreorlessyellow on the abdomen. Head hemispherical, but little 

 broader than the thorax. Antennae short, situated upon a slight con- 

 vexity of the front, first two joints short, third joint oval; arista basal, 

 bare, pubescent or loosely plumose. Face more or less i^ilose and polli- 

 no.se, but slightly excavated in i)rofile below the anteimge, straight, ob- 

 tuse below, not produced, near the middle with a small prominence. 

 Cheeks broad. Eyes more or less pilose, rarely nearly wholly bare, con- 

 tiguous in the male, or at least only separated by a sutural space (in 

 some exotic species sejjarated by a distinct interval). Thorax large. 

 Scutellum usually more or less translucent. Abdomen convex, elliptical, 

 longer and broader than the thorax. Legs strong, the hind femora some- 

 times considerably thickened or dilated, the hind tibife more or less, 

 sometimes considerably arcuated. Marginal cell of wing closed ; third 



*Eri8tali8, a precious stone. 



