NORTH AMERICAN DIPTERA. 263 



pleiirse ; scutellum black, sjjines yellow ; halteres green. Abdomen varies from a 

 bright green to greenish yellow, or bright yellow, with an irregular black dorsal 

 sti'ipe, forming on the second, third and fourth segments a series of keystone- 

 shajjcd markings, that on the fourth being usually the largest, stripe ending with 

 a triangular spot at the base of the fifth segment; venter green. Legs yellow. 

 Wings hyaline, veins yellow, discal cell emits two veins; third longitudinal vein 

 simple. 



9 . — Face, front and vertex broad, shining black, with white pile, more con- 

 spicuous in patches on the orbits; inferior orbits yellow; occiput with thick 

 whitish pubescence. Thorax black, with short yellowish white pubescence ; the 

 abdominal stripe usually wider than in the male, so that the green on the third, 

 fourth and fifth segments consists only of a narrow lateral, and on the fifth a 

 posterior margin. 



Southeastern Pennsylvania and southern New Jersey, June and 

 July, common; Francoiiia, N. H. (Mrs. Slosson) ; Connecticut and 

 Virginia, June 13 (Williston) ; Algonquin, 111. (Dr. Nason) ; Custer, 

 S. D. ( Aldrich) ; West Point, Neb., June 24 (Univ. Neb.) ; Kansas 

 (E. W. Guilding) Day; Georgia (Wiedemann); southern Georgia 

 (Morrison); Colorado (Riley); Texas (J. B. Smith); Springfield, 

 Mass. (Dimmock); Agricultural College, Michigan (Lowe); Mur- 

 freesborough, N. C, June 8. 



The above description is based on a series of over forty specimens. 

 Between the smaller specimen determined as 0. virgo by Loew, and 

 a somewhat larger one, the type of his 0. plebeja, I cannot draw 

 the line. The color of the antenniB are variable, the third joint is 

 sometimes reddish, exce])t the tip ; in others it is wholly dark brown, 

 while others show intermediate conditions. 



Odoutoiiiyia piliiiiaiia Loew (PI. iv, figs. 11, 12). 



Odontomi/ia pUiiiiaiM Loew, Centur. vi, 27 ; Day, Proc. Acad. Nat. Sci. Phila. 



1882, 83. 



Length 9 mm. ; wing 7 mm 9 • — Face, front and vertex black, shining, with 

 whitish pile, which is more conspicuous in patches along the orbits ; a spot on 

 the lower part of the facial orbit and two small spots below the ocelli on each 

 side of the frontal fossa yellow ; occiput with dense whitish pubescence. An- 

 tenuie red, tip of the third joint black ; proboscis black. Thorax black, with a 

 dense aureus pubescence, whitish on the pleurae ; scutellum black, spines yellow • 

 halteres green. Abdomen greenish yellow, with a black dorsal stripe, narrow on 

 the first and second, and expanding to three times this width on the third and 

 fourth ; fifth with an anterior central spot, leaving a posterior and lateral margin 

 of uniform width : venter green, or greenish yellow. Legs yellow. Wings 

 hyaline, veins yellow, third lougitudinal with branch ; discal cell emits two valid 

 and one rudimentary vein ; four posterior cells and one submarginal. 



% . — Face, frontal and vertical angle black, with sparse whitish pile ; ocelli 

 yellow, facial protuberance prominent, obtusely cariaate ; the abdominal stripe 

 not as wide on the third and fourth segments as in the female. 



TiRANS. AM. ENT. SOC. XXII. JULY, 1895. 



