1G4 BULLETIN 31, UNITED STATES NATIONAL MUSEUM. 



Face concealed beueath dense \vbitisli or yellowish pollen and wliitish 

 pile, concave below the auteunte ; a large oval spot connected with the 

 narrow oral margin, and the cheeks, shining black. Front in female 

 distinctly narrowed toward the vertex, at the narrowest part only a 

 little more than half as wide as at the base of the antennae; in well-pre- 

 served specimens dusted on the sides, more lightly in the middle, leav- 

 ing the vertex and jnst above the antennae shining, in the middle a slen- 

 der brown stripe and above on each side an oval black spot; pile above 

 blackish, below whitish. Frontal triangle with longer yellowish pile; 

 shining in the middle. Eyes nearly bare, the pile being short and con- 

 lined to the upper i)art. Antennae brownish black, third joint some- 

 what reddish ; arista red, briefly pilose toward the base. Thorax a deep 

 blue black, shining; jjile light yellowish, short, not abundant, but more 

 so on the pleurae. Scutellum scarcely reddish above. Abdomen shin- 

 ing bluish black ; the second segment on the sides sometimes yellowish, 

 and in the same specimens similar, but more faintly colored spots on 

 the sides of the third segment; the shining fascia of the second segment 

 interrupted in the male, entire in the female, in front narrowly, behind 

 broadly opaque black, without a shining triangular spot; third seg- 

 ment very narrowly in front, more broadly behind with entire velvety 

 fasciae ; fourth segment with a black fascia behind ; fifth segment 

 in female and the hypopygium in male wholly shining; the second, 

 third, and fourth segments very narrowly yellow behind. Legs black ; 

 the base of hind femora in the female and sometimes so in the male, the 

 basal half of anterior and posterior tibiae, rather more than half of the 

 middle tibiae, and the basal joints of the middle tarsi, yellow. Wings 

 hyaline, the immediate base, and a large spot near the middle covering 

 the cross- veins, brown ; in some specimens the brown of the middle is 

 confined to a narrow fascia across the base of the discal cell and origin 

 of the third vein. 



Thirty specimens. 



£ristalis latifrons. 



Eristalis latifrons Loew, Centur., vi, 65. 



Erifitalis stipator Osten Sacken, West. Dipt., 336 ; Williston, Proc. Am. PhiL Soc, 

 XX, 319. 



Hahitat. — California, Kansas, Arizona, Colorado, New Mexico, Texas! 

 ^ , 9 . Length, 9 to 14'"'". Face a little concave below the antennae, 

 concealed beneath dense yellowish-white i)olleu, and the pile of the 

 same color; in the middle with a rather broad shining bare stripe; the 

 cheeks also bare and shining black. Antennae black, third joint brown- 

 ish-black ; arista reddish yellow, bare. Eyes pilose, contiguous in the 

 male, the suture between them rather short (about half as long as the 

 interval between the apex of the frontal triangle and the root of the an- 

 tennae); front in female rather broad, the sides a little convergent above, 

 grayish pollinose, beset with dense grayish-white ]ule, shining along 



