GRTALIDiE — RIVELLIA. 95 



dinal vein is less arcuated towards the small crossvein than in 

 It. viridulans. The coxae and feet are dark-yellow ; the hind 

 tibiae, towards their end, grow gradually, but very slightly, mure 

 brownish-yellow ; the tarsi, from about the basis of the third 

 joint, dark brown. 



Hub. Texas (Belfrage). 



Observation. — The present species differs from all the pre- 

 ceding ones by the more pure and brilliant metallic-green color. 

 Varieties of 11. Jlavimana, with very pale feet, are nearest to it ; 

 but such specimens have at least the hind tibias, with the excep- 

 tion of the extreme basis and the extreme tip, brown. Moreover, 

 they differ from It. micans by the coloring of the first basal cell, 

 which is hardly perceptibly tinged with gray at its extreme basis 

 only, while in the latter species it is infuscated up to the last 

 third of the second basal cell. 



7. R. pallida n. sp. % J. — (Tab. VIII, f. 8.) FLavo-testacea, 

 Rivelliae micanti aequalis, reliquis speciebus minor, fasciis alarum nigro- 

 fuscis. 



Yellowish brick-red, of the size of R. micans, but smaller than the other 

 species; the crossbarids of the wings blackish -brown. Long. corp. 

 0.14—0.15 ; long. al. 0.13. 



Yellowish brick-red. Head concolorous ; front more ferru- 

 ginous ; on each side with a narrow border of white pollen. 

 Antennae of the same color with the remainder of the body, only 

 the third joint a little blackish at the extreme tip. One of my 

 specimens has the first two segments of the abdomen black at the 

 basis ; but this color seems to have originated after death, being 

 produced by the contents of the abdomen. Ovipositor not darker, 

 or but a little darker, than the rest of the abdomen. Feet dark- 

 yellow ; last two, at the utmost last three, joints of the tarsi 

 brown. Knob of the halteres brown. The picture of the wings 

 reminds of that of R. jlavimana, but instead of black it is 

 blackish-brown ; the costal cell is tinged with brown at the 

 spot only where the first crossband has its beginning, elsewhere 

 it is of a ding}' yellowish ; the root of the first basal cell shows, 

 as in It. flavimana, no dark coloring ; the first and the second 

 crossbands usually reach very near the fifth longitudinal vein. 

 This species is easily recognized by its smaller size and lighter 

 coloring. 



Eab. Washington, D. C. (Osten-Sacken.) 



