90 D1PTERA OF NORTH AMERICA. [PART III. 



wing, Walker gives the breadth of the wings from apex to apex, 

 a datum which is to be obtained only by approximation. This 

 breadth in 0. Ortoeda is said to be three, in O. quadrifasciata 

 four lines, a difference which is somewhat considerable, but, 

 owing to its uncertain nature, not to be relied upon exclusively 

 for separating the two species, as the female of R. viridulans 

 really has longer wings than the male. The quotation from 

 Harris's Catalogue has been introduced upon the authority of 

 Walker, who seems to have had original specimens of this 

 author ; but as the species has never been described, the quo- 

 tation might as well have been omitted. That Herina rufitarsis 

 Macq. belongs here is not doubtful. I have been able to com- 

 pare a typical specimen of Tephritis melliginis Fitch. 



Observation 2. — The following species agree so much with 

 R. viridulans in the breadth of the front, the shape and the 

 length of the antennas, and in the venation, that every statement 

 about these points would be useless. In speaking of the picture 

 of the wings, a statement about the points of difference will be 

 more useful towards discriminating the species than a detailed 

 description. 



3. R. quadrifasciata Macq. %. — (Tab. VIII, f. 5.) Thorace 

 viridi, capite prseter occiput, abdomine, pedibus, 1 alteribusque lnteis. 



Thorax green ; the head, with the exception of the occiput, the abdomen, 

 the feet, and the halteres, dark-yellow. Long. corp. 0.2; long. al. 0.19. 



Syn. Herina quadrifasciuta Macq. Suites, etc., II, p. 433, B. 



Head dark-yellow, the occiput metallic dark-green. Front 

 dusky red, with a narrow border of white pollen on each side. 

 Antennae dark yellowish-red ; the third joint, with the exception 

 of the root, brown; blackish towards the tip. Falpi dark-yellow. 

 Thorax, including the scutellum, of a blackish-green, metallic 

 coloring, shining. Abdomen dark-yellow-, more brownish-yellow 

 towards its end. Coxae and feet dark-yellow ; hind tibia? yel- 

 lowish-brown ; the last four joints of the front tarsi, and the last 

 three, more seldom the last four, joints of the middle and hind 

 tarsi infuscated. Halteres dark-yellow. The crossbands on the 

 wings as narrow and nearly in the same position as in R. viridu- 

 lans, but less dark ; the first band is narrower and crosses the 

 fourth longitudinal vein but very little ; the second reaches not 



