12 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



13. Lamellee long, fore coxae entirely yellow Icztus Loew. 



Lamellae short, fore coxae more or less infuscated 14 



14. Third antennal joint entirely deep black. . .dissimilipes, sp. nov. 

 Third antennal joint more or less yellow 15 



15. Abdomen of male metallic violet cyaneus, sp. nov. 



Abdomen of male bronze green 16 



16. All the coxae blackish abbreviatus Loew. 



Apical half of fore coxae yellow lamellatus Loew. 



10. Pelastoneurus neglectus, sp. nov. 



Plate I, Fig. 14. 



Female. Length 4 mm.; length of wing 3 mm. Palpi, and face below the 

 transverse suture, glistening with silver white dust. Between the suture and 

 the insertions of the antennae the dust is golden yellow. Antennae yellow 

 even to the tip of the third joint, which is distinctly pointed. Arista very 

 long, scarcely tapering, plumose on its apical two-thirds which are black, the 

 basal third being yellow. Front golden green in the middle, passing into 

 violet towards the superior orbits. Postocular cilia silvery white. Thorax 

 metallic green with violet reflections posteriorly. Prealar depressions glisten- 

 ing with thick silvery white dust. There are two distinct black spots on 

 either side, one mesial to the silvery depression and another at the postero- 

 lateral edge of the thorax. Scutellum metallic green, with a dark line down 

 its center. Abdomen dull metallic green above, with black incisures, more 

 cupreous on the sides and venter, covered with black hairs. Each segment 

 bearing a large patch of silvery white dust on its lateral surface. This dust 

 covers the entire sixth segment, which is small and partially concealed. 

 Pleurse metallic green, above thinly, below more thickly covered with white 

 dust. Fore coxae entirely yellow, with black hairs on their front surfaces; 

 middle coxae with yellow apical halves and basal halves dusted with white; 

 hind coxae yellow, with only their extreme bases dark. Legs entirely yellow, 

 tarsi but very slightly infuscated towards their tips. Wings brownish hya- 

 line, with the typical neuration of the genus. Tegulae and halteres yellow, the 

 former with black cilia. 



Two females, one from the vicinity of Chicago, 111. (July 

 6, 1895); the other from Milwaukee, Wis. (June 28, 1895). 



This species may be readily recognized by the very long 

 and scarcely tapering arista, and by the third joint of the 

 antenna being pointed and entirely yellow, at least in the 

 female. 



II. Pelastoneurus cognatus Loew, 



Two females taken in sweepings near Chicago, 111., 

 July 5, 1895, and May 8, 1896, agree very closely with 

 Loew's description of this species. 



