178 DIPTERA OF NORTH AMERICA. [PART II. 



5. C. affinis LOEW. and 9 Viridis, nitens, tegularum ciliis nigris, 

 femoribus nigris viridi-uaicantibus, summo anteriorum apice ex flavo 

 piceo. 



. Oculis contiguis, tertio antennarum articulo subobliquo, tibiis anticis 



ex flavo piceis. 

 9 . Tibiis anterioribus ex flavo piceis. 



Shining green, cilia of the tegulae black ; femora black with green lustre ; 



the extreme tip of the four anterior femora yellow-brownish. 

 > . Eyes contiguous ; the third joint of the antennae but little oblique ; the 



fore tibiae yellow-brownish. 

 J. The four anterior tibiae yellow-brownish. Long. corp. 0.09 0.10. 



Long. al. 0.10. 



SYN. Chrysotus affinis LOEW, Neue Beitr. VIII, 64, 4. 



Male. It is so much like the male of C. obliquus, that a state- 

 ment of the differences will be sufficient for its recognition. The 

 third joint of the antenna? is visibly smaller and less oblique ; the 

 hind femora have upon the second part of their under side a 

 greater number of bristle-like black hairs ; finally the hair upon 

 the hind tibia? is much longer ; the feet are considerably darker ; 

 fore tibiae more yellowish-brown than yellow and towards their 

 tips distinctly dusky ; middle tibia? often almost brown-black, but 

 always with a yellowish-brown basis ; middle tarsi entirely black- 

 brown ; fore tarsi only near the basis of a pale brown color. I 

 have not discovered any other differences. 



Female. I have only a single female, which I think belongs 

 here. It resembles the female of the preceding species very much, 

 only .the fore tibia? are more of a brownish-yellow color and dusky 

 towards the tip ; the middle tibia? are still darker than the fore 

 tibia? and the hind tibia? are like those of the male, black. The 

 third joint of^the antenna? is somewhat smaller than in the females 

 of C. obliquus. 



Hob. Middle States. (Osten-Sacken.) 



6. C. Tividus, nov. sp. . Viridis, nitens, ciliis tegularum nigris, 

 femoribus nigris viridi-micantibus, genibus tibiisque flavis, maris oculis 

 distantibus et costa alarum non incrassata. 



Green, shining, cilia of the tegulae black, femora black with green lustre, 

 knees and tibiae yellow ; in the male, the eyes separated and the costa 

 not thickened. Long. corp. 0.09. Long. al. 0.09. 



Metallic-green, bright, but on the upper side of the thorax with 

 a rather thick brownish-yellow dust and therefore more dull. The 



