142 BULLETIN 31, UNITED STATES NATIONAL MUSEUM. 



clotlietl with short white pile; on the sides and border of scutelhim 

 with rather long" yellowish white bristles; the scntellum itself more yel- 

 lowish translucent. Abdomen nearly bare; yellow translucent, or even 

 subtransparent at the base, towards the tip often brownish, perhaps 

 more or less the result of drying; the posterior margins of second, 

 third, and fourth segments each with a rather small, quadrangular black 

 spot, on either side near the lateral margin; on the second and third 

 segments they are broader than long, and often Joined by a posterior 

 brown fiiscia; the second and third segments sometimes in the middle 

 behind with a distinct black spot; pile very short, near the posterior 

 margins of the segments black, elsewhere pallid. Legs yellow, tip of 

 anterior tibite and tip of all the tarsi blackish. Wings quite hyaline; 

 a small brownish spot near the tip of auxiliary vein ; the third vein 

 reaches the costa near tip of wing, the second vein joins the first very 

 near its end, sometimes beyond it, so that the marginal cell is open. 

 Four specimens, compared with the types at Cambridge. 



Volucella satur. (Plate VI, Ogs. 11, 12 h.) 



Volucdla siitiir Osteu Sacken, West. Dipt., 333. 

 Habitat. — Kansas, Colorado! Utah (O. S.j. 



5,9. Length, 9 to 10""". Antennae light brown, arista reddish, 

 loosely plumose, third joint nearly as long as the arista, very narrow 

 in the male, a little broader and more expanded in the female. Face 

 yellow, a black stripe runs obliquely from the lower corner of the eye 

 to the anterior oral margin ; behind it the cheeks are narrow ; i)rofile 

 of the face nearly straight in the male, in the female a little receding 

 on the lower part, the depression below the antenna^ is very slight. 

 Frontal triangle of the male yellow, beset with black pile, the vertex 

 black; in the female the front is broad, of a greenish tinj^e, as if under- 

 lying the yellow; a slender median yellow line runs from the antennee 

 towards the yellow vertex; the ocelli are on a cordiform black spot. 

 Eyes pilose. Thorax blackish-green ; on each side between humerus and 

 scntellum a rather broad, dull, honey -yellow stripe, with a short black 

 stieak in the middle; in front of the scntellum a yellowish, rather ob- 

 scure parallelogram, emarginate anteriorly ; pleurte with a large yellow 

 si)ot, beset with yellow pile. Scntellum yellow, with black hairs on the 

 edge. Abdomen honey-yellowish ; first segment black, second and 

 third with a narrow black hind border; the black border of the second 

 segment is connected with the black of the first segment by a black 

 longitudinal stripe, which is narrow in the female, broad and triangu- 

 larly expanded anteriorly in the male; fourth segment with a broad 

 black hind border; fifth segment black. Femora black; knees and 

 two-thirds of the tibiie biownish-yellow, the last third black, or, on the 

 intermediate ])air, brownish ; tarsi reddish at base, brownish or black 

 at tip. Wings grayish-hyaline; stigma yellowish, with a small pale- 

 brown cloud; cross- veins at the base of first and last posterior cells, and 



