212 BULLETIN UNITED STATES GEOLOGICAL SURVEY. 



coxfe, yellow. Knob of the halteres brownish on the under side. Wings 

 with a uniform slightly brownish tinge. 



Hab. — San Eafael, Cal., May 29. One specimen. 

 The antennae of R. Jionestus ( S ) seem to be like those of B. ruficolUs 

 {$) Hal., of which I regret not to have a specimen for comparison ; only 

 instead of having 34-35 joints, they have 22-23. The eyes are notched 

 on the inner side, as described in Walker, List, etc., v, p. 104. The col. 

 oring of the body of B. honestus is exactly like that of a specimen from 

 Illinois, which I have, and believe to be a mere variety of R. ohscuripen- 

 nis Lw. 



The North American RacMceri at present known may bo grouped 

 thus : — 



Antennte not pectinate: 



riifieollis Hal. — Atlantic States. 

 honestus n. sp. — California. 

 Antennae pectinate in the male, not pectinate in the female : 



varipes Loew. — Cuba. 

 Antennae pectinate in both sexes : 

 ohsGuripennis Loew. — Illinois. 

 nigripcdpus Loew. — Mexico. 



Family STEATIOMYID.^. 



Chloromyia vmiDis (syn. Sargus viridis Say). — A number of speci- 

 mens taken between San Eafael and Saucelito, Marin County, Cal., 

 April 2, agree with the specimens from the Atlantic States. The same 

 occurs in Colorado (P. E. Uhler). 



The name Ghrysomyia Macq., 1834, cannot be maintained for the 

 genus to which Sargus viridis belongs, as there is an earlier Ghrysomyia 

 Eob. Desv., 1830, among the Muscidce. I reinstate, therefore, the name 

 Chloromyia, introduced by Mr. Dnucan (Magaz. Zool. and Bot., 1837). 



OxYCERA CROTCH! n. sp., 9 . — Abdomen with three lateral yellow 

 spots on each side and an apical triangular one, all connected by a 

 narrow yellow margin; femora black, with yellow tip; tibiae and 

 tarsi yellow. Length 8™™. 



Female. — Face and front yellow, with a broad black stripe in the 

 middle ; posterior orbits yellow ; vertex, cheeks under the eyes, and 

 occiput black. Antennae : basal joints black (the rest wanting). Thorax 

 black, opaque; a yellow stripe from the humerus to the antescutellar 

 callus is interrupted a little beyond the middle, a pair of narrower 

 yellow stripes on the dorsum slightly expanded in front and not reach- 

 ing beyond the transverse suture; scutellum yellow, the base black; 

 pleurae with a large yellow spot in front of the wings, and a smaller 

 oblong one under it; the black opaque abdomen has a subtriangular 

 yellow spot on each side of the second segment, a larger, semi-elliptical 

 spot on each side of the third segment, a somewhat similar, but smaller, 

 pair of spots on the fourth segment, a large triangular spot on the last 



